Versioned tarball with tests

[jayvdb]

It would be helpful if this library and https://github.com/jeff00seattle/pyfortified-logging included tests in a versioned tarball, so they can be used for testing of distro packages.

The simplest way to do that is use GitHub releases which create a tarball for the tag, with everything included.

Even better is the add the tests to the PyPI sdist. This can be mostly automated by using check-manifest which can update MANIFEST.in to ensure it is a complete archive.