Added Code Climate badge
Refactored Mongoid::Enum::ClassMethods for readability
Refactored accessor definition into methods
Updated travis config, removed RBX and notifications
Added ruby 2.1.1 to travis config
Tweaked accessors conditional
Merge pull request #5 from thetron/update/cleanup

Quest for the 4.0 GPA
Support mongoid 4.0.0.beta1.

* Will be upgrade to the 4.0.0 stable.