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/GMbK0jne
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