Add Python 3.8, 3.9, 3.10

[kclowes]

What was wrong?

Adds support for Python 3.8, 3.9, 3.10. Also updates a bunch of dependencies.

Issue #37

How was it fixed?

Added tests for all the added Python versions. Also:

• adds lint tests for all versions as a smoke test for dev dependency installs.
• adds odds and ends from the ethereum-python-template-repo

To-Do

• [x] Clean up commit history

• [x] Add entry to the release notes

Cute Animal Picture

[kclowes]

@fselmo fixed! Thanks!

[fselmo]

@fselmo fixed! Thanks!

ah, nice! I guess this is what was missing...

[kclowes]

ah, nice! I guess this is what was missing...

Yeah, I hope that's not too heavy-handed 🤔 I guess we'll find out