Bullet Train Roles provides a Yaml-based configuration layer on top of
CanCanCan. You can use this configuration file to simplify the definition of
many common permissions, while still implementing more complicated permissions
in CanCanCan's traditional app/model/ability.rb.

Additionally, Bullet Train Roles makes it trivial to assign the same roles and
associated permissions at different levels in your application. For example, you
can assign someone administrative privileges at a team level, or only at a
project level.