Modernize rspec syntax

This takes lessons from the rubocop-rspec issue[1] and applies them to
write a more modern style. This should be more compatible with future
versions of rspec.

[1]: rubocop/rubocop-rspec#1231

spec/acceptance/certs_spec.rb

@@ -2,7 +2,9 @@
 
 require 'spec_helper_acceptance'
 
-describe 'trusted_ca' do
+describe 'trusted_ca', order: :defined do
+  fqdn = fact('fqdn')
+
   context 'failure before cert' do
     # Set up site first, verify things don't work
     it 'sets up apache for testing' do
@@ -21,40 +23,37 @@
       apply_manifest(pp, catch_failures: true)
     end
 
-    describe command("/usr/bin/curl https://#{fact('hostname')}.example.com:443") do
-      its(:exit_status) { is_expected.to eq 60 }
+    specify do
+      expect(command("/usr/bin/curl https://#{fqdn}:443")).
+        to have_attributes(exit_status: 60)
     end
 
-    describe command("cd /root && /usr/bin/java SSLPoke #{fact('hostname')}.example.com 443") do
-      its(:exit_status) { is_expected.to eq 1 }
+    specify do
+      expect(command("cd /root && /usr/bin/java SSLPoke #{fqdn} 443")).
+        to have_attributes(exit_status: 1)
     end
   end
 
   context 'success after cert' do
-    it 'works idempotently with no errors' do
-      pp = <<-EOS
-      class { 'trusted_ca': }
-      trusted_ca::ca { 'test': source => '/etc/ssl-secure/test.crt' }
-      EOS
-
-      # Run it twice and test for idempotency
-      apply_manifest(pp, catch_failures: true)
-      apply_manifest(pp, catch_changes: true)
+    it_behaves_like 'an idempotent resource' do
+      let(:manifest) do
+        <<-PUPPET
+        class { 'trusted_ca': }
+        trusted_ca::ca { 'test': source => '/etc/ssl-secure/test.crt' }
+        PUPPET
+      end
     end
 
-    describe package('ca-certificates') do
-      it { is_expected.to be_installed }
-    end
+    specify { expect(package('ca-certificates')).to be_installed }
 
-    # https://github.com/rubocop/rubocop-rspec/issues/1231
-    # rubocop:disable RSpec/RepeatedExampleGroupBody
-    describe command("/usr/bin/curl https://#{fact('hostname')}.example.com:443") do
-      its(:exit_status) { is_expected.to eq 0 }
+    specify do
+      expect(command("/usr/bin/curl https://#{fqdn}:443")).
+        to have_attributes(exit_status: 0)
     end
 
-    describe command("cd /root && /usr/bin/java SSLPoke #{fact('hostname')}.example.com 443") do
-      its(:exit_status) { is_expected.to eq 0 }
+    specify do
+      expect(command("cd /root && /usr/bin/java SSLPoke #{fqdn} 443")).
+        to have_attributes(exit_status: 0)
     end
-    # rubocop:enable RSpec/RepeatedExampleGroupBody
   end
 end