Code review comment for ~smoser/git-ubuntu:fix/run-all-tests

If you want to keep _test functions in the same files, we can do that.
But I would suggest that then we add a pytestrc file.
We could write content to a temp file and then execute with '-c <filename>'
so that it would all be contained in

./snap-wrappers/wrappers/git-ubuntu-self-test