Reformat code with black and add check on push

[climbus]

Can We reformat code with black?

I've checked on my fork and looks that everything is ok. Of course We must have cleat situation with branches and merging.

https://github.com/climbus/rope/actions/runs/1250987372

[lieryan]

Hi @climbus,

Thanks for bringing this up. I wasn't able to use your branch as-is, so I've re-ran black and made a new commit instead. I have git attribute you as the commit author when making the commit to credit you for bringing this topic up and for doing the original blackening. I hope you don't mind.