mongoid/mongoid — pull request #3614 by arthurnn (2014-04-23 18:19:29+00:00)
Title: Use ActiveModel::Model

include ActiveModel::Model instead of the 4 modules different AM models.

After @carlosantoniodasilva talk at RailsConf I realized Mongoid should be using AM::Model to try to be as close as possible of AR API.

@durran :shipit: ?