We've relied on setuptools to convert our alpha/beta tags to

a/b. However, this generates an annoying warning. To avoid this, we

now handle normalization as part of string generation.
The package also now defines a python_requires, which specifies all

versions of Python that are supported. This will help pip determine

which versions of kgb are eligible for installation in the future.

Built the package. Didn't see any warnings.
Inspected the metadata for the new Python requirements.