What does this implement/fix? Explain your changes.

Drops support for and all references to Python 2.

Does this close any currently open issues?

Can't find it right now, but I think we had an issue discussing this.

Any other comments?

-/-

Checklist

Check all those that are applicable and complete.

• Make sure to include one or more tests for your change
• If an enhancement PR, please create docs and at best an example
• Add yourself to AUTHORS
• Updated the CHANGELOG