[RFC] Using "black" compatible formatting

[pfalcon]

@andrewleech mention using the Black tool for formatting in #8 (comment) .

My immediate reaction to its motto of "The Uncompromising Code Formatter" is "uh-oh". But it has pretty well and convincing written docs, which is fun to read due to interspersed passages like "If you're paid by the line of code you write, you can ...", and the right reasonable choices made in the questions like strings delimiters, line length, etc.

So, well, let's keep it on the radar.

[pfalcon]

To disclose my intentions with this ticket - I don't intend to adopt the black formally, the purpose of this ticket is to "corner" contributors into using the right string delimiters, "". As in: "You really have no choice, if we used black, you'd have to use double-quotes. Well, yeah, we don't use it really, but please assume we do (will)."