Code analysis toolset integration.

Add code analysis gems.

Add raketask to run them.

Add internationalization for spanish.

Add rubocop config.

Add rubocop fixes.

Fixes for rails_best_practices.

Reek code analysis fixes.

Make sure demeters law applies even if relation is nil.
Merge pull request #51 from espadium/add_codereview_tools

Code analysis toolset integration.