(PUP-3086) Add spec testing for face component

Add spec tests for Puppet face component, mainly around error checking.
Due to the use of `puppet module list`, the behavior of the `modules`
and `server` actions are not very feasible to test via spec testing.

Additionally, make a few minor changes to the gem file, and make a
small change in `check_required_features` to reflect the fact that
this module will no longer support anything earlier than Ruby 1.9.
(PUP-3068) Add spec testing for pops component

Prior to this commit there was no testing around the pops component.
Since most of the API in the pops component is private, there aren't
very many things to test, so add just a few test cases.

Additionally rename a previous spec file and make some changes to
the Gemfile.