Apply

----------------

----------------

- Update tox.ini for latest tox.
[stefan]

- Add GitHub CI workflow.
[stefan]

- Add .readthedocs.yaml file.
[stefan]

- Pin sphinx and sphinx-rtd-theme versions in docs extra.
[stefan]

----------------

- Add Python 3.8-3.10 to tox.ini. Remove old Python versions.
[stefan]

- Replace deprecated ``python setup.py test`` in tox.ini.
[stefan]

- Remove deprecated ``test_suite`` from setup.py.
[stefan]

- Move metadata to setup.cfg and add a pyproject.toml file.
[stefan]

- Include tests in sdist but not in wheel.
[stefan]

----------------

- Add MANIFEST.in.
[stefan]

- Release as wheel.
[stefan]

----------------

- Support Python 2.6-3.6 without 2to3.
[stefan]

- Add a LICENSE file.
[stefan]

----------------

- Remove setuptools from install_requires because it isn't.
[stefan]