Release process

[GuillaumeSeren]

Hey,
we have discussed quite a bit with @flokli about the release process, we're still no decided for the details,
so in this issue we will continue the discussion here in the open, so everyone can participate.

Actual elements:

• A CI deployement of the release on Pypi.
• A good / detailled Changelog is really important for user and maintainers.
• A working tarball release (github tarball ModuleNotFoundError: No module named 'afew.version' #283)
• Nightly builds ?

[djwf]

I'm not sure nightly builds contribute much given that anyone can pull the latest git. Nightly builds matter more in compiled languages, and for this I think detailed instructions on how to use afew directly from the repository would be more important (and more useful to get testers).