Pre-commits conflict with each other

[danelphick]

The formatters black and reorder-python-imports conflict with each other, which means the pre-commits always fail. This is because black inserts a new line between the docstring at the top and reorder-python-imports removes it. See psf/black#4175 for details.

There doesn't appear to be a workaround using these two tools, but one suggestion is to change from reorder-python-imports to isort which has black-compatibility as a goal. It would cause a bunch of churn as they have different sort policies, but the current files need sorting anyway according to reorder-python-imports. If you're interested, I'll go ahead and create a PR.

[nathanmarlor]

@danelphick I haven't had much time at all to spend on EM of late, so appreciate whatever you can do to keep it up to date :)