By candidate .
$ pip install .
$ cron_parser -h
$ cron_parser HH:MM < file
Or (given this program takes stdin):
$ streaming_output | cron_parser HH:MM
Installs pytest and runs the suit in a py36 environment. Tox is the correct choice because this is a locally run package.
$ tox
Creates a pip installable zip file in ./dist/ (not using this for this test because you presumably want the non-packaged tests).
python setup.py sdist --formats=zip