Swap unittest2 for stdlib unittest so test work on modern python versions

[robotadam]

unittest2 won't work on anything > Python 3.9, and it's only necessary for old versions that have reached EOL.

This change is the bare minimum to get tests to run with pytest, but the README calls out python setup.py test, which doesn't work anymore as that feature was removed from setuptools. You'll want to add pytest to dev requirements and possibly set up tox for multi-version testing.

[ShreyaThapa]

Thanks for the PR, @robotadam! All tests pass with stdlib unittest. 🙏

Just something to note, should unittest2 = "*" also be removed from the [dev-packages] section in Pipfile since we won't be using it any longer?

Once that's addressed and the new merge conflicts are resolved, this should be ready for another review and merge! 🚀

[robotadam]

@ShreyaThapa Is the Pipfile even used? The github actions didn't include it, so it looked like something that was abandoned.

[ShreyaThapa]

Good point, @robotadam! I checked and the Pipfile is indeed abandoned - the project officially uses requirements.txt for everything (CI, README, etc.).

Once the merge conflicts are resolved, this will be ready to merge. 🚀

[robotadam]

Merge conflict resolved!