Formatting code with Black

[mgaitan]

I propose to enforce code formatting with Black

Consider the arguments developed in https://github.com/django/deps/blob/master/accepted/0008-black.rst

• There's no debate about the usefulness of readable code formatting.
• With automated code formatting, this workload can be transferred to computers, saving human bandwidth for higher value-added activities.
• It's about making our Python code look as much as possible like what everyone else in the Python community writes.

[tburrows13]

Yes please! I suppose the best way would be to run it on the entire project locally and submit that as a PR. Then use some tool like https://github.com/marketplace/actions/black-code-formatter to keep it consistent?

[mgaitan]

Implemented here mgaitan#1

I'll open the proper PR after #1077 be merged.