Adding linting, formatting rules and doc

[sharky98]

Hello,

I played around with my default dev tools with Python. Here the list and why. Feel free to accept, refuse or cherry-pick.

• pipenv => I prefer pipenv over pip since it is similar to NPM in NodeJS that only the root requirements are present and you can split between dev and prod packages.
• bandit => Looking for security issues in the code.
• black => Formatting (without settings).
• isort => Sort the import in a specific way.
• pydocstyle => Make sure all elements are documented.
• pylint => Enforce coding standard.
• mypy => Static typing checker. This one I was not able to run since SpiffWorkflow is not typed. I was thinking about doing some typing on SpiffWorkflow, if my time allows it.

[danfunk]

There is a lot good value in here Bruno, will need to unpack this, but all the linting tools feel like a good idea, not just here, but more importantly in SpiffWorkflow itself. The big thing hanging me up is Pipenv -- were trying to convert our projects over to Poetry, which is the dependency manger de jure as far as I can tell.

[sharky98]

Hello! Yep, Poetry is the way to go, just learned about this one yesterday :)