Installed CanCan

I added the CanCan gem to the gemfile and installed CanCan’s ability
model. We will use CanCan to define user roles in our applicaiton.
Created Roles Class

I created the roles class to define various roles in application. Users
and roles have a HABTM relationship so one user can have many roles and
many users can share the same roles. The roles database model is simply
a string for each role.
Added Role Method to Users

I added a convience role method to users. This method will easily test
if a user has a particular role. For example, ‘user.role? :admin’ will
only return true if a user is an admin.
Added tests for user role relationship

I added tests for the user role relationship.
Fixed user roles relationship tests

I should have tested them before I commited. They have been fixed.
Added tests for role? method

I added tests for the role method on the user model. I probably should
have written the tests first, but oh well.
Merge branch 'create-roles'