Unbreak the mypy tests

[dokterbob]

Making it easier to make (for contributors) and accept (for maintainers) contributions.

[ntninja]

mypy stuff breaks with like every second update, but it should be fixed again I agree.

[ntninja]

Want to delay this until after 0.8 since it's likely a lot of work.

[c0llab0rat0r]

Want to delay this until after 0.8 since it's likely a lot of work.

This will be significantly less work if the minimum Python version is raised to 3.7. #258

[c0llab0rat0r]

If #257 and #260 are merged, it would resolve this issue.

[c0llab0rat0r]

@ntninja with the merge of #261, I believe this is now resolved, though there is more work to do to remove type hint warning suppression.

[ntninja]

Yes it can be better of course, but it a much better situation than what we started out with thanks to you!