removed spurious ChatController related stuff prior to adding omniauth
Added support for Google OAuth2 via omniauth.  If a user is an
Instructor or Administrator subclass, and if they have an email field
exactly matching their email on Google, they can login and do admin
things.
Required adding email field (and for efficiency, index) on users.
Created Cuke tests for authentication and a Cuke Before action to avoid
messing up scenarios that implicitly assume admin login.
Added factories for other user types (admin, instructor).
force SSL in production
use Rack::SSLEnforcer to selectively do SSL
use Rack::SSLEnforcer to selectively do SSL
use Rack::SSLEnforcer to selectively do SSL
rebased to master, added all of us to authorized admins list in migration
skip before filter that checks authentication for UsersController
Merge branch 'feature/AF/omniauth'