Compare Test Results To Snapshot

[bforbis]

I am currently trying to add a build to our FHIR server's development branches that will automatically run inferno and prove that a previously passing inferno test did not start failing on the new branch. Since we are currently not in a state where ALL inferno tests are passing, this is a bit difficult to do with the current command line interface, as they would currently require that all required tests for each opt-in test sequence passes in their entirety.

One solution to this would be to provide a test snapshot into the run command which would be compared with the test output. If a previously passing test starts failing, it would have a non-zero exit code. Tests that were failing in the snapshot that continue to fail would be ignored.