Switched to basic python containers, onto which the ci
steps simply install poetry.
This takes a little more processing time during pipeline running (~16s
per step),
but also gives much more flexibility in container usage.
Switching to nox for test automation across multiple python versions.
Fixing mypy library stubs missing for some imported libraries.
Program can now be invoked through poetry for development purposes,
invoke as follows from main directory: `poetry run move`.
Alternatively, can still be invoked via `python run.py <nomie-json>` and
now via `./run.py <nomie-json>` which uses system default python
installation. For now both commands are only mainly useful from the
poetry development virtual environment itself.