Fix double request parsing for default actions

[tiagopog]

Fixes #28 and #44

TODO

• Fix double request instantiation for default actions by overriding the JSONAPI::ActsAsResourceController#process_request method – it's no longer required to override the default actions in order to skip this behavior;
• Write specs covering the case for default actions;
• Improve README.md;
• Improve code doc;
• Update version;
• Update .travis.yml.

[tiagopog]

👀 @yellow5 @delner

[delner]

So I just spotted this in the Rails 5.0.1 release notes:

Added ActionController::Parameters#deep_dup which actually creates a params copy, instead of refereing to old references in params.

Fixes #26566.

rails/rails#26566

It's possible that using deep_dup on that params object instead of dup in 5.0.1 might circumvent this entire issue. Worth trying?

[tiagopog]

Cool! I didn't know about the existence of that method, thanks for sharing.

It's certainly an easy fix for that issue of changing the internals of params, however, it would still make double instantiation on the @request instance variable , which I'm also trying to fix with this PR.

The fix proposed here – override the JSONAPI::ActsAsResourceController#process_request – will probably be temporary since the proper fix would be a memoization on @request.

[yellow5]

👍 👏