Adds specs for state#display_name for localization

spec/localizer_test_model_deprecated_style.yml

@@ -4,3 +4,10 @@ en:
       localizer_test_model:
         aasm_state:
           opened: "It's open now!"
+
+fr:
+  activerecord:
+    attributes:
+      localizer_test_model:
+        aasm_state:
+          opened: "C'est ouvert maintenant!"

spec/localizer_test_model_new_style.yml

@@ -3,3 +3,9 @@ en:
     attributes:
       localizer_test_model:
         aasm_state/opened: "It's open now!"
+
+fr:
+  activerecord:
+    attributes:
+      localizer_test_model:
+        aasm_state/opened: "C'est ouvert maintenant!"

spec/models/active_record/localizer_test_model.rb

@@ -24,11 +24,19 @@ describe 'localized state names' do
     state = LocalizerTestModel.aasm.states.detect {|s| s == :opened}
     expect(state.localized_name).to eq("It's open now!")
     expect(state.human_name).to eq("It's open now!")
+    expect(state.display_name).to eq("It's open now!")
+
+    I18n.with_locale(:fr) do
+      expect(state.localized_name).to eq("C'est ouvert maintenant!")
+      expect(state.human_name).to eq("C'est ouvert maintenant!")
+      expect(state.display_name).to eq("C'est ouvert maintenant!")
+    end
   end
 
   it 'should use fallback' do
     state = LocalizerTestModel.aasm.states.detect {|s| s == :closed}
     expect(state.localized_name).to eq('Closed')
     expect(state.human_name).to eq('Closed')
+    expect(state.display_name).to eq('Closed')
   end
 end