Fix the bug that serializer could not be found if the association's s…

[Hirurg103]

…erializer is namespaced but the model is not

[fix #2295]

[bf4]

Hmm, built failure appears unrelated, just JRUBY

  1) Failure:
ActiveModelSerializers::CacheTest#test_uses_adapter_in_cache_key [/home/travis/build/rails-api/active_model_serializers/test/cache_test.rb:305]:
--- expected
+++ actual
@@ -1 +1 @@
-{:id=>"post", :title=>"New Post", :body=>"Body"}
+nil

[Hirurg103]

Hi @bf4 could you please review this PR and merge it if it is OK

[bf4]

Yes, I'll get to it today

[Hirurg103]

Thank you @bf4

[bf4]

Didn't do it yet. was writing some epic postgresql at the office

[Hirurg103]

Hi @bf4, it happens, no problem at all

[bf4]

Confirmed your test is good. Could no reproduce jruby failure with my local version of JRuby and Rails 4.1

[Hirurg103]

Thanks for reviewing and merging my fix, @bf4 ! Can I close #2295 now?