Remove Fuubar

Previously, we used to include Fuubar to make our RSpec output prettier,
but it has since been removed from the RSpec configuration, which makes
the inclusion of the Fuubar gem obsolete. Removed the gem from the
Gemfile and updated the bundle.

https://trello.com/c/9ldd9z5R
Remove gemset

Previously, we used to rely on gemsets within Ruby to separate our gems
from our global gems, which is no longer required with the advent of
Bundler. Removed the gemset name from the repo so that one is no longer
defined.

https://trello.com/c/9ldd9z5R