Created the admin controller and views
Merge branch 'master' into admin-interface
Got basic admin interface functionality working
Fleshed out the users admin page
Added edit account functionality
Fixed rspec tests
Implemented basic roles functionality
Added an admin link (for admins only)
Created semi-functional role dropdowns

I also updated the user controller to display a more appropriate
message, reflecting the fact that accounts must be approved.
Finished up the user admin interface