Log Message:
py-flake8: updated to 3.9.0

3.9.0 -- 2021-03-14
-------------------

You can view the `3.9.0 milestone`_ on GitLab for more details.

New Dependency Information
- Pyflakes has been updated to >= 2.3.0, < 2.4.0 (See also `GitLab!466`_)
- pycodestyle has been updated to >= 2.7.0, < 2.8.0 (See also `GitLab!467`_)

Deprecations
- Drop support for python 3.4 (See also `GitLab!457`_)

Features
- Add ``--no-show-source`` option to disable ``--show-source`` (See also
  `GitLab!441`_)

Bugs Fixed
- Fix handling of ``crlf`` line endings when linting stdin (See also
  `GitLab!461`_)