Wait until audit phase to load needed files.

This solves two of the problems we are currently seeing:

1. RSpec configuration shared by audits and our own spec tests cause undesired behavior when running `rspec`,
2. Serverspec types interfere with Chef DSL (e.g., `package`).

\cc @tyler-ball @sersut 
Yeah, we'll have to move that test into here. Otherwise, it's last writer wins...