Fix test/utils package

Erroneously removed unittest import from __init__.py
Ignore unittest import warning

Specifically ignore the warnings from flake8 for tests/utils/__init__.py. Its bit of a false warning, probably because of the try/except & if conditions
auto_discover test

Remove the import that was causing flake8 to warn. Replace with the actual method that is being called thats required for the test.
diff tests

Add space back in assertions that was removed by auto-formatting