black + flake8 formatting

[avivajpeyi]

black and flake8 help keeping code formatting. We can automate (and enforce) the formatting with pre-commit.

See this.

I'm happy to set this up along with a CI test to ensure that pushed code has been formatted.

Thoughts?

[tzdwi]

Hmm... I like this in principle, but I'm worried it might add more barriers to entry for new folks who will see black/flake8 doing their thing and be a little lost. But I might be totally misunderstanding what these tools do! Would you want to start up a convo in the Slack and see what other folks think?