Update mccabe to 0.7.0

[pyup-bot]

This PR updates mccabe from 0.6.1 to 0.7.0.

Changelog

0.7.0

* Drop support for all versions of Python lower than 3.6

* Add support for Python 3.8, 3.9, and 3.10

* Fix option declaration for Flake8

Links

• PyPI: https://pypi.org/project/mccabe
• Changelog: https://pyup.io/changelogs/mccabe/
• Repo: https://github.com/pycqa/mccabe