Extend `black` formatting to look in the test directory too

[liamhuber]

@XzzX pointed out it doesn't actually parse the tests directory! It's just here to improve readability, so IMO let's make the test suite more readable too!

This is low priority for me, but I am happy to make the PR -- should just be extending the path variable here. In the meantime I'll open it immediately as an issue to make room for any dissent.

[XzzX]

@XzzX pointed out it doesn't actually parse the tests directory! It's just here to improve readability, so IMO let's make the test suite more readable too!

This is low priority for me, but I am happy to make the PR -- should just be extending the path variable here. In the meantime I'll open it immediately as an issue to make room for any dissent.

Oh no. I thought this is a trivial 5 minute change. Unfortunately, this is in the global actions repo... That complicates things.

[XzzX]

Let's check the feedback #138 🙈