Building, testing and publishing wheels via GitHub Actions CI/CD

[domi007]

This CI/CD config file allows building, testing and publishing wheels of pysctp. It is limited intentionally to only create x86_64 and i686 builds for CPython 3.6-3.11 for manylinux architecture. Any of these limitations could be lifted by editing the wheels.yml file, and especially changing the CIBW_SKIP variable.
The publish job was taken almost directly as-is from pycrate.

EDIT: Naturally for this to be fully functional secrets/tokens for Pypi must be added the same way they are already added to the pycrate project. Also I guess an official tag with 0.7.2 not just the change in VERSION would make things complete after potential merge :)