Merge pull request #17 from lucasrenan/master

running tests with mongoid 3.1.x
Revert "Merge pull request #15 from nardstae/master"

This reverts commit c4a482d13136a55230d07cf5735c07f33794cacb, reversing
changes made to d2007f37962cb79254ecd2340e378da77f5804cd.
Updates
  - removing locales, I think that it has to be handle outside this gem
  - upgrade gems
we don't need to print mongoid version when running tests anymore
just creates a changelog