Add cancan to project
Add authenticated controller as a base class for any
controller that needs authentication/authorization
Respond to html and json to use the respond_with method in controllers
Display flash message if present
Add roles and user roles join model, with controller
Add users controller and add relationships to roles and user_roles to user model
Add admin, staff and user roles to seeds
Add route to users controller
Run migrations
Add ability class with definitions
Show link to users path if user has permission to view users