diff --git a/.rubocop.yml b/.rubocop.yml
index cd8d1a0..081f3b5 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,231 +1,8 @@
-# Relaxed.Ruby.Style
+require:
+  - solidus_dev_support/rubocop
 
-AllCops:
-  Exclude:
-    - 'spec/dummy/**/*'
-    - 'vendor/bundle/**/*'
-  TargetRubyVersion: 2.1
-
-# Sometimes I believe this reads better
-# This also causes spacing issues on multi-line fixes
-Style/BracesAroundHashParameters:
-  Enabled: false
-
-# We use class vars and will have to continue doing so for compatability
-Style/ClassVars:
-  Enabled: false
-
-# We need these names for backwards compatability
-Style/PredicateName:
-  Enabled: false
-
-Style/AccessorMethodName:
-  Enabled: false
-
-# This has been used for customization
-Style/MutableConstant:
-  Enabled: false
-
-Style/ClassAndModuleChildren:
-  Enabled: false
-
-Style/GuardClause:
-  Enabled: false
-
-Style/WordArray:
-  Enabled: false
-
-Style/ConditionalAssignment:
-  Enabled: false
-
-Performance/Count:
-  Enabled: false
-
-Style/RaiseArgs:
-  Enabled: false
-
-Style/OpMethod:
-  Enabled: false
-
-# We can use good judgement here
-Style/RegexpLiteral:
-  Enabled: false
-
-# Unicode comments are useful
-Style/AsciiComments:
-  Enabled: false
-
-Lint/EndAlignment:
-  Enabled: false
-
-Style/ElseAlignment:
-  Enabled: false
-
-Style/IndentationWidth:
-  Enabled: false
-
-Style/AlignParameters:
-  Enabled: false
-
-Style/ClosingParenthesisIndentation:
-  Enabled: false
-
-Style/MultilineMethodCallIndentation:
-  Enabled: false
-
-Style/IndentArray:
-  Enabled: false
-
-Style/IndentHash:
-  Enabled: false
-
-Style/AlignHash:
-  Enabled: false
-
-# From http://relaxed.ruby.style/
-
-Style/Alias:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylealias
-
-Style/BeginBlock:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylebeginblock
-
-Style/BlockDelimiters:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styleblockdelimiters
-
-Style/Documentation:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styledocumentation
-
-Style/DotPosition:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styledotposition
-
-Style/DoubleNegation:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styledoublenegation
-
-Style/EndBlock:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styleendblock
-
-Style/FormatString:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styleformatstring
-
-Style/IfUnlessModifier:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styleifunlessmodifier
-
-Style/Lambda:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylelambda
-
-Style/ModuleFunction:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylemodulefunction
-
-Style/MultilineBlockChain:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylemultilineblockchain
-
-Style/NegatedIf:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylenegatedif
-
-Style/NegatedWhile:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylenegatedwhile
-
-Style/ParallelAssignment:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styleparallelassignment
-
-Style/PercentLiteralDelimiters:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylepercentliteraldelimiters
-
-Style/PerlBackrefs:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#styleperlbackrefs
-
-Style/Semicolon:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylesemicolon
-
-Style/SignalException:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylesignalexception
-
-Style/SingleLineBlockParams:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylesinglelineblockparams
-
-Style/SingleLineMethods:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylesinglelinemethods
-
-Style/SpaceBeforeBlockBraces:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylespacebeforeblockbraces
-
-Style/SpaceInsideParens:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylespaceinsideparens
-
-Style/SpecialGlobalVars:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylespecialglobalvars
-
-Style/StringLiterals:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylestringliterals
-
-Style/SymbolProc:
-  Enabled: false
-
-Style/WhileUntilModifier:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#stylewhileuntilmodifier
-
-Lint/AmbiguousRegexpLiteral:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#lintambiguousregexpliteral
-
-Lint/AssignmentInCondition:
-  Enabled: false
-  StyleGuide: http://relaxed.ruby.style/#lintassignmentincondition
-
-Lint/HandleExceptions:
-  Exclude:
-    - 'Rakefile'
-
-Metrics/AbcSize:
-  Enabled: false
-
-Metrics/BlockNesting:
-  Enabled: false
-
-Metrics/ClassLength:
-  Enabled: false
-
-Metrics/ModuleLength:
-  Enabled: false
-
-Metrics/CyclomaticComplexity:
-  Enabled: false
-
-Metrics/LineLength:
-  Enabled: false
-
-Metrics/MethodLength:
-  Enabled: false
-
-Metrics/ParameterLists:
+RSpec/MultipleMemoizedHelpers:
   Enabled: false
 
-Metrics/PerceivedComplexity:
+RSpec/LetSetup:
   Enabled: false
diff --git a/app/decorators/solidus_payment_method_by_zone/spree/payment_method_decorator.rb b/app/decorators/solidus_payment_method_by_zone/spree/payment_method_decorator.rb
index 9c8ab91..a0aee10 100644
--- a/app/decorators/solidus_payment_method_by_zone/spree/payment_method_decorator.rb
+++ b/app/decorators/solidus_payment_method_by_zone/spree/payment_method_decorator.rb
@@ -1,9 +1,16 @@
 # frozen_string_literal: true
 
+<<<<<<< Updated upstream
 module SolidusPaymentMethodByZone
   module Spree
     module PaymentMethodDecorator
       extend ActiveSupport::Concern
+=======
+module Spree
+  module PaymentMethodDecorator
+    def self.prepended(base)
+      base.has_and_belongs_to_many :zones, join_table: 'spree_payment_method_zones'
+>>>>>>> Stashed changes
 
       included do
         has_and_belongs_to_many :zones, join_table: 'spree_payment_method_zones'
diff --git a/app/decorators/solidus_payment_method_by_zone/spree/zone_decorator.rb b/app/decorators/solidus_payment_method_by_zone/spree/zone_decorator.rb
index e59b357..cfd8042 100644
--- a/app/decorators/solidus_payment_method_by_zone/spree/zone_decorator.rb
+++ b/app/decorators/solidus_payment_method_by_zone/spree/zone_decorator.rb
@@ -1,9 +1,17 @@
 # frozen_string_literal: true
 
+<<<<<<< Updated upstream
 module SolidusPaymentMethodByZone
   module Spree
     module ZoneDecorator
       extend ActiveSupport::Concern
+=======
+module Spree
+  module ZoneDecorator
+    def self.prepended(base)
+      base.has_and_belongs_to_many :payment_methods, join_table: 'spree_payment_method_zones'
+    end
+>>>>>>> Stashed changes
 
       included do
         has_and_belongs_to_many :payment_methods, join_table: 'spree_payment_method_zones'
diff --git a/config/routes.rb b/config/routes.rb
index 53e2eeb..59d0244 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Spree::Core::Engine.routes.draw do
   # Add your extension routes here
 end
diff --git a/db/migrate/20190208214252_solidus_payment_method_by_zone_create_payment_method_zones.rb b/db/migrate/20190208214252_solidus_payment_method_by_zone_create_payment_method_zones.rb
index 0506b82..6748fa8 100644
--- a/db/migrate/20190208214252_solidus_payment_method_by_zone_create_payment_method_zones.rb
+++ b/db/migrate/20190208214252_solidus_payment_method_by_zone_create_payment_method_zones.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class SolidusPaymentMethodByZoneCreatePaymentMethodZones < SolidusSupport::Migration[5.0]
   def change
     create_table :spree_payment_method_zones do |t|
diff --git a/lib/generators/solidus_payment_method_by_zone/install/install_generator.rb b/lib/generators/solidus_payment_method_by_zone/install/install_generator.rb
index 357281b..5b682f6 100644
--- a/lib/generators/solidus_payment_method_by_zone/install/install_generator.rb
+++ b/lib/generators/solidus_payment_method_by_zone/install/install_generator.rb
@@ -1,16 +1,26 @@
+# frozen_string_literal: true
+
 module SolidusPaymentMethodByZone
   module Generators
     class InstallGenerator < Rails::Generators::Base
       class_option :auto_run_migrations, type: :boolean, default: false
 
       def add_javascripts
-        append_file 'vendor/assets/javascripts/spree/frontend/all.js', "//= require spree/frontend/solidus_payment_method_by_zone\n"
-        append_file 'vendor/assets/javascripts/spree/backend/all.js', "//= require spree/backend/solidus_payment_method_by_zone\n"
+        append_file 'vendor/assets/javascripts/spree/frontend/all.js',
+          "//= require spree/frontend/solidus_payment_method_by_zone\n"
+        append_file 'vendor/assets/javascripts/spree/backend/all.js',
+          "//= require spree/backend/solidus_payment_method_by_zone\n"
       end
 
       def add_stylesheets
-        inject_into_file 'vendor/assets/stylesheets/spree/frontend/all.css', " *= require spree/frontend/solidus_payment_method_by_zone\n", before: /\*\//, verbose: true
-        inject_into_file 'vendor/assets/stylesheets/spree/backend/all.css', " *= require spree/backend/solidus_payment_method_by_zone\n", before: /\*\//, verbose: true
+        inject_into_file 'vendor/assets/stylesheets/spree/frontend/all.css',
+          " *= require spree/frontend/solidus_payment_method_by_zone\n",
+          before: %r{\*/},
+          verbose: true
+        inject_into_file 'vendor/assets/stylesheets/spree/backend/all.css',
+          " *= require spree/backend/solidus_payment_method_by_zone\n",
+          before: %r{\*/},
+          verbose: true
       end
 
       def add_migrations
@@ -18,11 +28,13 @@ def add_migrations
       end
 
       def run_migrations
-        run_migrations = options[:auto_run_migrations] || ['', 'y', 'Y'].include?(ask('Would you like to run the migrations now? [Y/n]'))
+        run_migrations = options[:auto_run_migrations] || ['', 'y', 'Y'].include?(
+          ask('Would you like to run the migrations now? [Y/n]')
+        )
         if run_migrations
           run 'bundle exec rake db:migrate'
         else
-          puts 'Skipping rake db:migrate, don\'t forget to run it!'
+          Rails.logger 'Skipping rake db:migrate, don\'t forget to run it!'
         end
       end
     end
diff --git a/lib/solidus_payment_method_by_zone.rb b/lib/solidus_payment_method_by_zone.rb
index 897b92f..0cab6f0 100644
--- a/lib/solidus_payment_method_by_zone.rb
+++ b/lib/solidus_payment_method_by_zone.rb
@@ -1,4 +1,9 @@
+# frozen_string_literal: true
+
 require 'solidus_core'
+require 'solidus_backend'
 require 'solidus_support'
 require 'deface'
+
+require 'solidus_payment_method_by_zone/version'
 require 'solidus_payment_method_by_zone/engine'
diff --git a/lib/solidus_payment_method_by_zone/engine.rb b/lib/solidus_payment_method_by_zone/engine.rb
index f4165ec..0425a65 100644
--- a/lib/solidus_payment_method_by_zone/engine.rb
+++ b/lib/solidus_payment_method_by_zone/engine.rb
@@ -1,20 +1,18 @@
+# frozen_string_literal: true
+
+require 'solidus_payment_method_by_zone'
+
 module SolidusPaymentMethodByZone
   class Engine < Rails::Engine
-    require 'spree/core'
+    include SolidusSupport::EngineExtensions
+
     isolate_namespace ::Spree
+
     engine_name 'solidus_payment_method_by_zone'
 
     # use rspec for tests
     config.generators do |g|
       g.test_framework :rspec
     end
-
-    def self.activate
-      Dir.glob(File.join(File.dirname(__FILE__), '../../app/**/*_decorator*.rb')) do |c|
-        Rails.configuration.cache_classes ? require(c) : load(c)
-      end
-    end
-
-    config.to_prepare(&method(:activate).to_proc)
   end
 end
diff --git a/lib/solidus_payment_method_by_zone/factories/state_factory.rb b/lib/solidus_payment_method_by_zone/factories/state_factory.rb
index 7598e9b..9f22c84 100644
--- a/lib/solidus_payment_method_by_zone/factories/state_factory.rb
+++ b/lib/solidus_payment_method_by_zone/factories/state_factory.rb
@@ -1,6 +1,11 @@
 # frozen_string_literal: true
+<<<<<<< Updated upstream
  
 eval(ENV.fetch('FACTORY')).define do
+=======
+
+FactoryBot.define do
+>>>>>>> Stashed changes
   factory :state_ja, class: 'Spree::State' do
     transient do
       country_iso { 'MX' }
diff --git a/lib/solidus_payment_method_by_zone/version.rb b/lib/solidus_payment_method_by_zone/version.rb
index 29da5ab..a24fdef 100644
--- a/lib/solidus_payment_method_by_zone/version.rb
+++ b/lib/solidus_payment_method_by_zone/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module SolidusPaymentMethodByZone
   VERSION = '1.0.1'
 end
diff --git a/solidus_payment_method_by_zone.gemspec b/solidus_payment_method_by_zone.gemspec
index be8e6d3..eab2d2e 100644
--- a/solidus_payment_method_by_zone.gemspec
+++ b/solidus_payment_method_by_zone.gemspec
@@ -19,6 +19,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency 'solidus_core', '>= 2.2'
   s.add_runtime_dependency 'deface', '~> 1.0'
 
+<<<<<<< Updated upstream
   s.add_development_dependency 'capybara'
   s.add_development_dependency 'poltergeist'
   s.add_development_dependency 'coffee-rails'
@@ -34,4 +35,21 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'selenium-webdriver'
   s.add_development_dependency 'solidus_support'
   s.add_development_dependency 'solidus_dev_support'
+=======
+  s.files = files.grep_v(%r{^(test|spec|features)/})
+  s.test_files = files.grep(%r{^(test|spec|features)/})
+  s.bindir = 'exe'
+  s.executables = files.grep(%r{^exe/}) { |f| File.basename(f) }
+  s.require_paths = ['lib']
+
+  solidus_version = ['>= 2.6', '< 4']
+
+  s.add_dependency 'deface', '~> 1.0'
+  s.add_dependency 'solidus_core', solidus_version
+  s.add_dependency 'solidus_support', '~> 0.5'
+
+  s.add_development_dependency 'solidus_backend', solidus_version
+  s.add_development_dependency 'solidus_dev_support', '~> 2.5'
+  s.add_development_dependency 'solidus_frontend', solidus_version
+>>>>>>> Stashed changes
 end
diff --git a/spec/features/admin/payment_methods_spec.rb b/spec/features/admin/payment_methods_spec.rb
index 290a91e..f6c8444 100644
--- a/spec/features/admin/payment_methods_spec.rb
+++ b/spec/features/admin/payment_methods_spec.rb
@@ -5,9 +5,9 @@
 describe 'Payment methods admin page', type: :feature, js: true do
   stub_authorization!
 
-  context 'when create new payment method' do
-    let!(:mexico) { create(:zone, name: 'Mexico') }
+  let!(:mexico) { create(:zone, name: 'Mexico') }
 
+  context 'when create new payment method' do
     before do
       visit spree.new_admin_payment_method_path
     end
@@ -22,7 +22,7 @@
         check 'Mexico'
       end
       click_on('Create')
-      expect(page).to have_content("successfully created!")
+      expect(page).to have_content('successfully created!')
     end
   end
 end
diff --git a/spec/models/spree/order_spec.rb b/spec/models/spree/order_spec.rb
index 71b7773..862ccb2 100644
--- a/spec/models/spree/order_spec.rb
+++ b/spec/models/spree/order_spec.rb
@@ -7,11 +7,23 @@
   let(:usa) { Spree::Country.find_by(iso: 'US') }
   let(:us_zone) { create(:zone) }
   let(:mx_zone) { create(:zone) }
-  let!(:us_payment_method) { create(:check_payment_method, name: 'US method', zones: [us_zone]) }
-  let!(:mx_payment_method) { create(:check_payment_method, name: 'MX method', zones: [mx_zone]) }
+  let(:us_payment_method) do
+    create(
+      :check_payment_method,
+      name: 'US method',
+      zones: [us_zone]
+    )
+  end
+  let(:mx_payment_method) do
+    create(
+      :check_payment_method,
+      name: 'MX method',
+      zones: [mx_zone]
+    )
+  end
   let(:order) { create(:order_with_totals) }
 
-  before(:each) do
+  before do
     order.line_items << create(:line_item)
     us_zone.members.create(zoneable: usa)
     mx_zone.members.create(zoneable: mx)
@@ -19,58 +31,58 @@
 
   describe 'available_payment_methods' do
     it 'includes frontend payment methods' do
-      payment_method = Spree::PaymentMethod::Check.create!({
-        name: 'Fake',
-        active: true,
-        available_to_users: true,
-        available_to_admin: false
-      })
+      payment_method = Spree::PaymentMethod::Check.create!(
+        {
+          name: 'Fake',
+          active: true,
+          available_to_users: true,
+          available_to_admin: false
+        }
+      )
       expect(order.available_payment_methods).to include(payment_method)
     end
 
     it 'must not include payment methods for Mexico in addresses of US' do
-      expect(order.available_payment_methods).to include(us_payment_method)
       expect(order.available_payment_methods).not_to include(mx_payment_method)
     end
+  end
 
-    context 'with mexican address' do
-      let(:state) { create(:state_ja, country: mx) }
-      let(:address) { create(:address, city: 'Leon', state: state) }
-      let!(:order) { create(:order_with_totals, ship_address: address) }
+  describe 'with mexican address' do
+    let(:state) { create(:state_ja, country: mx) }
+    let(:address) { create(:address, city: 'Leon', state: state) }
+    let!(:order) { create(:order_with_totals, ship_address: address) }
 
-      it 'must include mx payment method' do
-        expect(order.available_payment_methods).not_to include(us_payment_method)
-        expect(order.available_payment_methods).to include(mx_payment_method)
-      end
+    it 'must include mx payment method' do
+      expect(order.available_payment_methods).to include(mx_payment_method)
+    end
 
-      context 'with address matching more than one zone with same payment method' do
-        let(:ja_zone) { create(:zone) }
+    context 'with address matching more than one zone with same payment method' do
+      let(:ja_zone) { create(:zone) }
 
-        before do
-          ja_zone.members.create(zoneable: state)
-          mx_payment_method.zones.push(ja_zone)
-          mx_payment_method.save
-        end
+      before do
+        ja_zone.members.create(zoneable: state)
+        mx_payment_method.zones.push(ja_zone)
+        mx_payment_method.save
+      end
 
-        it 'must include unique payment method' do
-          expect(order.available_payment_methods.count).to eq(1)
-        end
+      it 'must include unique payment method' do
+        expect(order.available_payment_methods.count).to eq(1)
+      end
 
-        it 'must include mx payment method' do
-          expect(order.available_payment_methods).to include(mx_payment_method)
-        end
+      it 'must include mx payment method' do
+        expect(order.available_payment_methods).to include(mx_payment_method)
       end
     end
+  end
 
-    context 'with address not matching zones' do
-      let(:ar) { create(:country, iso: 'AR') }
-      let(:caba) { create(:state_ja, country: ar, state_code: 'C') }
-      let(:address) { create(:address, city: 'Recoleta', state: caba) }
-      let!(:order) { create(:order_with_totals, ship_address: address) }
+  context 'with address not matching zones' do
+    let(:ar) { create(:country, iso: 'AR') }
+    let(:caba) { create(:state_ja, country: ar, state_code: 'C') }
+    let(:address) { create(:address, city: 'Recoleta', state: caba) }
+    let!(:order) { create(:order_with_totals, ship_address: address) }
 
-      it 'must not return any payment method' do
-        expect(order.available_payment_methods.count).to eq(0)
-      end
+    it 'must not return any payment method' do
+      expect(order.available_payment_methods.count).to eq(0)
     end
   end
 end
diff --git a/spec/support/capybara.rb b/spec/support/capybara.rb
new file mode 100644
index 0000000..47feb4f
--- /dev/null
+++ b/spec/support/capybara.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+Capybara.register_driver :headless_firefox do |app|
+  Capybara::Selenium::Driver.load_selenium
+  browser_options = ::Selenium::WebDriver::Firefox::Options.new
+  browser_options.args << '-headless'
+  Capybara::Selenium::Driver.new(app, browser: :firefox, options: browser_options)
+end
+
+Capybara.register_driver :headless_chrome do |app|
+  Capybara::Selenium::Driver.load_selenium
+  browser_options = ::Selenium::WebDriver::Chrome::Options.new.tap do |opts|
+    opts.args << '--headless'
+    opts.args << '--disable-gpu' if Gem.win_platform?
+    # Workaround https://bugs.chromium.org/p/chromedriver/issues/detail?id=2650&q=load&sort=-id&colspec=ID%20Status%20Pri%20Owner%20Summary
+    opts.args << '--disable-site-isolation-trials'
+  end
+  Capybara::Selenium::Driver.new(app, browser: :chrome, options: browser_options)
+end
+
+Capybara.javascript_driver = :headless_firefox
diff --git a/spec/support/database_cleaner.rb b/spec/support/database_cleaner.rb
new file mode 100644
index 0000000..82d657c
--- /dev/null
+++ b/spec/support/database_cleaner.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require 'database_cleaner'
+
+RSpec.configure do |config|
+  # Ensure Suite is set to use transactions for speed.
+  config.before(:suite) do
+    DatabaseCleaner.strategy = :transaction
+    DatabaseCleaner.clean_with :truncation
+  end
+
+  # Before each spec check if it is a Javascript test and switch between using
+  # database transactions or not where necessary.
+  config.before do
+    DatabaseCleaner.strategy = RSpec.current_example.metadata[:js] ? :truncation : :transaction
+    DatabaseCleaner.start
+  end
+
+  # After each spec clean the database.
+  config.after do
+    DatabaseCleaner.clean
+  end
+end