Upgrade to mongeez 0.9.4, add authentication support (#1)

I attempted to verify that the auth support worked, but wasn't able to do so.  Regardless of how I configured my users, I get `not authorized for update on mongeez-gorm.mongeez`.  Does this work for anyone?

If I can get confirmation that this at least doesn't break usage without authentication, I'm okay with merging it.

CC: @mhurne @aheiss1