Add session management, user registration, and some sample users
in the db seed.
Add review groups to partition users.
Stub out review controller.
Require users to register (instead of logging in with just their
andrewid). Ensure user's grading alias is not their andrewid.
Add LDAP integration to user model.
Add relationship in user model for those users that own groups. Display
group affiliation or error page in reviews.
Add and edit reviews.