use github actions to build Windows releases for pypi

[cmacdonald]

Dear @cvangysel please consider this PR for making binary Windows releases using GitHub actions.

I have test this using Github actions on my own fork to make a test pypi release.

To use this, you would need to:

• delete the line $Env:PYTRECEVAL_NAME_SUFFIX = "-craigm"
• create PyPi.org and test.pypi.org secrets and place them as github secrets to this repository (see https://packaging.python.org/guides/publishing-package-distribution-releases-using-github-actions-ci-cd-workflows/#saving-credentials-on-github), storing them as secrets names PYPI_PASSWORD and TEST_PYPI_PASSWORD
• to make a test release, select the publish github action

I further made the following changes:

• version is set in __init__.py, and copied into setup.py
• fixed another build warning related to setup.cfg
• version can be overridden for test.pypi releases.
• name can be overridden (necessary for my own testing)

You may wish to consider if you want to also build other binary wheel releases at this time (linux etc).

An in principle response would be appreciated - we need to have this for teaching commitments this summer.

Craig