Add a hash to consumer profiles.
Update some docblocks.
Store the profile hash whenever the profile is created or updated.
Assert that the profile_hash parameter to the UnitProfile constructor
works.
Convert the consumer profile hash to use json and sha256.
Fix a docblock.
Remove upgrade tests from run-tests.py.
Assert that the profile hash calculation handles non-ASCII profiles.
Condense the profile hashing code a bit.
Merge branch 'rbarlow-consumer_profile_hashing' into applicability-performance
Merge branch 'applicability-performance' into rbarlow-applicability_db_models
Modify the RepoProfileApplicabilityManager to have filter() and get() support.

Also, adds full test coverage to the manager and the model.