Prior to this commit, the beaker gem and all its dependencies were
being installed just to run spec tests. Excluding beaker when running
spec tests should make things go faster because we won't have to
install so many gems.
In order to ensure long term code quality, add a rubocop check to
the travis job which runs when a pull request is submitted. Do this
by adding a rake task for rubocop and setting up travis to run
both the spec rake task and the rubocop one.
Additionally, make a few changes to the .rubocop.yml file so it
will stop complaining about incorrect namespaces.
Hailee Kenney