Add simple github workflow.

[tompollard]

This pull request adds a github workflow that will run pytest on pull requests to main.

Currently there are no tests, so nothing really happens. Tests are added in #5.

[EthanSteinberg]

This looks mostly good. My main comment is that we also want to add a github workflow to publish packages, but that should be done in another PR.

[tompollard]

My main comment is that we also want to add a github workflow to publish packages, but that should be done in another PR.

Thanks Ethan, sounds good. Are you happy with the approach suggested below, where this workflow runs every time a change is pushed to a "release" branch?

https://docs.github.com/en/packages/managing-github-packages-using-github-actions-workflows/publishing-and-installing-a-package-with-github-actions#publishing-a-package-using-an-action

[EthanSteinberg]

Thanks Ethan, sounds good. Are you happy with the approach suggested below, where this workflow runs every time a change is pushed to a "release" branch?

That generally looks like the right approach, but I like the "on: release" workflow trigger better.

See https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#release or https://github.com/som-shahlab/femr/blob/main/.github/workflows/build.yaml#L4 for a full example.