Adopt tox for development and testing

[matthewfeickert]

Description

The tox automation project seems to be a very robust and stable testing automation framework, and I've recently learned form Anthony Sottile's videos (core dev of tox in addition to other things) that it can be quite useful for also getting a development environment up and running quickly.

Particularly relevant sections of the docs:

• Creating development environments using the --devenv option

Video links for reference (no captions :disappointed:):

• Introduction to tox
• tox --devenv

[matthewfeickert]

@alexander-held This may be of interest to you as well for cabinetry development.