mongoid/mongoid — pull request #3373 by simi (2013-11-06 16:35:11+00:00)
Title: Test ruby-head on Travis CI.

I don't see any reason why we are not testing `ruby-head` when we're testing `jruby-head`.

As a benefit maybe some problem related to https://github.com/mongoid/mongoid/issues/3372 will be found.