Top-level tests for profile resolver using real-world profiles

[galtm]

The OSCAL team is creating end-to-end tests for their implementations of the profile resolver. I suggest including some real-world examples among this test suite, if possible, such as the FedRAMP profiles from https://github.com/GSA/fedramp-automation.

As the profile resolver spec and code evolve, including real-world profiles in the test suite would have these benefits:

• Reduce the risk of a regression that negatively affects these profiles
• Make any expected incompatibilities clearer and more concrete to stakeholders
• Further enhance working relationship with FedRAMP team