Merge pull request #7854 from guilleiguaran/extract-rack-cache

Fix middleware cache tests enabling rack_cache

railties/test/application/middleware/cache_test.rb

@@ -49,6 +49,8 @@ module ApplicationTests
           get ':controller(/:action)'
         end
       RUBY
+
+      add_to_config "config.action_dispatch.rack_cache = true"
     end
 
     def test_cache_keeps_if_modified_since