upgrade to ruby 2.1.5

* https://trello.com/c/ZkOxHozD/401-ruby-2-1-5
Merge branch 'master' of https://github.com/thegarage/thegarage-template into update-ruby

# By Ryan Sonnek
# Via Ryan Sonnek
* 'master' of https://github.com/thegarage/thegarage-template:
  reorg css selector test
  fix method name
Merge branch 'update-ruby'

* update-ruby:
  upgrade to ruby 2.1.5