.. note::

   $ find sphinx tests LICENSE doc/conf.py -type f -exec sed -i '' -e 's/2007\-20../2007-2021/' {} \;
   $ git co sphinx/locale/**/*.js sphinx/templates/epub3/mimetype

The issue applied to Python 2 only. The current override is identical to
the CPython implementation:

https://github.com/python/cpython/blob/4b8cdfcb22fbeaab9d954cb693a7fb3362a382b6/Lib/distutils/cmd.py#L207-L215

Keep imports alphabetically sorted and their order homogeneous across
Python source files.

The isort project has more feature and is more active than the
flake8-import-order plugin.

Most issues caught were simply import ordering from the same module.
Where imports were purposefully placed out of order, tag with
isort:skip.

* Support --keep-going with BuildDoc setup command

This allows for `tox -e docs -- -n -W --keep-going`.