Python 3.9 Support #828
Description
There currently exists a rare crash condition that can occur with the combination of python 3.9.0 and pybind11 (for context see this ASWF thread or this pybind11 issue.
The tl;dr: There could be unexpected and unpredictable crashing in Python 3.9.0, this issue is set to be addressed in 3.9.1. After 3.9.1 is released we should enable CI for 3.9 and consider adding 3.9 to the badge in the readme.
We may also consider updating the python_requires to exclude 3.9.0, though we'd want to make sure we can do this in a way that signals to users why this is and steps to remedy (use 3.9.1 instead).