Add support for Python 3.10

[emilbonnek]

At the moment users will get:
ImportError: cannot import name 'MutableMapping' from 'collections' (C:\Python310\lib\collections\__init__.py)

This seems to be because of this dependency (line 4) which needs to be:
from collections.abc import MutableMapping

[dogweather]

Yep - I just got hit by this. Is there a workaround?

I'm thinking I can install an older python with pyenv, and create a virtualenv with it to run the app.

[sleao]

Yep - I just got hit by this. Is there a workaround?

I'm thinking I can install an older python with pyenv, and create a virtualenv with it to run the app.

You can just open the file and change the from collections import MutableMapping to from collections.abc import MutableMapping. It worked for me.