Deleting old versions from PyPI

[gadomski]

I wasn't very careful about the size and number of wheels that I was uploading to PyPI during the development of this project, and I hit the 10GB maximum today. I'm working on ways to slim things down (https://github.com/gadomski/stacrs/issues/350) and I'll need to clean up space to be able to publish again. Deleting just the wheels (and not the releases) is a very slow, point-and-click process AFICT, so I'm going to just delete a bunch of old versions. If this breaks something for you, please let me know and I can help out, but I doubt it will affect many people since this repo isn't widely used yet.