chore: update pg, activerecord, activesupport versions

Author: ryanatwork

postshift.gemspec

@@ -24,12 +24,12 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '>= 2.2.2'
 
-  spec.add_dependency 'pg', '>= 0.20.0'
-  spec.add_dependency 'activerecord', '~> 5.0'
-  spec.add_dependency 'activesupport', '~> 5.0'
+  spec.add_dependency 'pg', '>= 1.5'
+  spec.add_dependency 'activerecord', '~> 6.1'
+  spec.add_dependency 'activesupport', '~> 6.1'
 
   spec.add_development_dependency 'bundler'
-  spec.add_development_dependency 'rake', '>= 12.3.3'
+  spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec', '~> 3.0'
   spec.add_development_dependency 'factory_bot', '>= 4.8'
   spec.add_development_dependency 'database_cleaner', '~> 1.7'