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
Update sample environment variables

Previously, some sensitive data was being stored in the application's
sample environment variables, which was presenting a security issue. The
variables have been updated to use dummy values.

https://trello.com/c/ss5habYR