Merge pull request #2340 from rails-api/action_dispatch_response_media_type

Configure `ActionDispatch::Response#content_type` behavior on Rails 6+

.travis.yml

@@ -12,7 +12,7 @@ ruby_supported_versions:
 
 jruby_supported_versions:
   - &jruby_9_1 jruby-9.1.17.0
-  - &jruby_9_2 jruby-9.2.7.0
+  - &jruby_9_2 jruby-9.2.8.0
   - &jruby_head jruby-head
 
 jdk_supported_versions:

test/support/rails_app.rb

@@ -9,6 +9,10 @@ module ActiveModelSerializers
       config.action_controller.perform_caching = true
       config.action_controller.cache_store = :memory_store
 
+      if Rails::VERSION::MAJOR >= 6
+        config.action_dispatch.return_only_media_type_on_content_type = true
+      end
+
       config.filter_parameters += [:password]
     end