Python 3.8 CancelledError

[rbotman]

Python 3.8 included a change to the base class for CancelledError.
See: https://bugs.python.org/issue32528

Just removing '.futures' from line 5 avoids an error in 3.8
from asyncio.futures import CancelledError

Here's the error:
ImportError: cannot import name 'CancelledError' from 'asyncio.futures'

[sirk390]

Fixed in version 0.41, commit 7f38f41