Python 3.8 and 3.9 unit tests do not assert coverage

[ipwnponies]

The tox setup only asserts that all test code must be run. What about the actual package code 😭 ?

pytest-antilru/tox.ini

Lines 46 to 47 in d64dc5f

	coverage run -m pytest tests/
	coverage report --fail-under 100 --include 'tests/*'