Update rails in Gemfile to 4.0.4
Update slim-rails and depended gems
Update config files after Rails upgrade
Merge pull request #135 from fs/update-rails-to-4-0-4

Upgrade to latest Rails > 4.0.0
Update rails_best_practices, rubocop
Fix quality warnings
Merge pull request #138 from fs/update-quality-tools

Update quality tools
Merge branch 'master' into make-sure-brakeman-exit-on-warn

* master:
  Fix quality warnings
  Update rails_best_practices, rubocop
  Update config files after Rails upgrade
  Update slim-rails and depended gems
  Update rails in Gemfile to 4.0.4