Fix foreman function to accept username/password/url data rather than hardcoding
Fix external fixtures to the refs we use
Clean up

* Fail on unsupported operating systems / families.
* Remove unused puppet_basedir parameter from init.pp
* Drop support for Fedora < 17
* Use :params instead of pre_condition in tests (where possible)
Add Amazon Linux support

This assumes all Amazon Linux is el6 based. It also explicitly fails on
unsupported operating systems / families.