Integrate `tox` testing for local compatibility check on multiple python versions

[mpvanderschelling]

Problem

Testing locally if f3dasm is working with multiple versions of python could be useful to check the compatibility before committing

Solution

Using the tox package, this can be done easily. However maybe using both venv and mamba environments can create an issue ..

[mpvanderschelling]

I've decided to hold off tox integration for now, as I'm using mamba as a environment manager and this needs to integrate with tox