Update Travis: remove SQLite, add Ruby 2.1, remove old Rubygems workaround
Bundle update for Rails 3.2.21, mysql2 0.3.17, eventmachine 1.0.4.
Pin gems for Ruby 1.8.7: i18n ~> 0.6.x, execjs gem ~> 2.0.x.
Merge pull request #308 from sodabrew/travis_ruby2.1

Update Travis: remove SQLite, add Ruby 2.1, etc.