Publishing via tagging commits

[lfwa]

Hi everyone (and welcome to our discussion board),

carbontracker has now been updated to using build and setuptools for building and packaging. This also means that we now store all project metadata in pyproject.toml.

To ease publishing, I have a created a new workflow that automatically builds carbontracker and distributes it on PyPi and Test PyPi when new releases are created. You can create a new release by tagging your commit with a version number such as 1.1.7 and it will then build and publish on PyPi. If you prepend the tag by test-, e.g. test-1.1.7, then it will instead publish the build to Test PyPi.

NOTE that this works on all branches, so REFRAIN from tagging your commits on other branches with version numbers that do not have the prefix test- since it will then be published on PyPi even if you are not working on the master branch.

This change also means we no longer store any explicit version numbers in files such as the previous __version__.py: they are only stored in commit tags.

How to: Create a release (and tag your commit) through GitHub web interface

1. Click on Releases on the right-hand side of the main repository page and press "create a new release".
2. Click "Choose a tag" then write your tag with the version number, e.g. test-1.1.7 and click "Create new tag on publish"
   
3. Write a release title and add a changelog/description (you can also click "Generate release notes" to automatically generate the changelog from commits and pull requests).
4. Publish your release!
   This should automatically trigger the workflow that builds and publishes it.

[lfwa]

One caveat: I am not entirely sure how branching affects releases and whether the main page will show all releases even if they were created from a branch other than master. If they all do show up on main page, we might want to rethink how we publish to Test PyPi since tagging a commit with test-... every time we want to test a feature (from another branch) will likely lead to a ton of test-releases down the road that we don't necessarily want everyone to see.

If anyone wants to experiment with this or have any suggestions, feel free to share. :)