Include license file in the generated wheel package

Created originally on Bitbucket by jdufresne (Jon Dufresne)

Changesets for this Pull Request have not been imported, because it had been already declined on Bitbucket. Marked as closed by the import user.

The wheel package format supports including the license file. This is done using the [metadata] section in the setup.cfg file. For additional information on this feature, see:

https://wheel.readthedocs.io/en/stable/index.html#including-the-license-in-the-generated-wheel-file