Apply JSONAPI

[dmitrytrager]

We could try to implement jsonapi spec.

We need a make decision https://github.com/rails-api/active_model_serializers vs. https://github.com/cerebris/jsonapi-resources

These changes should be merged only after confirmation from @NikolaevSergey & @RamilGabdrakhmanov.

References:

• http://jsonapi.org
• http://girders.org/blog/2016/08/26/building-rails-apis-with-jsonapi-and-jsonapi-resources/

[IlkhamGaysin]

Can i take this one?

[timurvafin]

@IlkhamGaysin sure, please coordinate your work with Vlad

JSONAPI::Utils can be yet another option.