Sync with source repo

[szhan]

PyRQA is the work of Tobias Rawald (who doesn't seem to have much presence on GitHub) and colleagues. The source repo resides in PyPi. The latest version of the module is 8.0.0, which was released on Feb. 21, 2021.

I put up a copy here on GitHub because I found it useful for an old project. However, I have not used the module since the project was done. so the repo here is outdated and it has been out of sync with the source for a while now. It may be useful for some folks to examine and fork the source code on GitHub, so I may sync the repos when I find time.