🐛 Fix status process in tests

[hillairet]

There was an issue in the way the success of the tests is reported. For example if mypy was missing it would say:

######### CHECK TYPING: OK
mypy command not found

Not great.
Now it will say "FAILED"

Also I cleaned up the dependencies in the pyproject.toml and added the poetry.lock cause we want consistent testing and that's how it'll be in apps.

Finally I removed a warning in pytest by adding an entry in the pyproject.toml.