Move to GitHub Actions

[phansch]

This gets rid of both the AppVeyor build and the TravisCI build. The Travis CI build stopped triggering some time ago. Instead, we're now using GitHub Actions for both Windows and Linux builds.

Closes #227

[phansch]

I'm.. at a total loss why it doesn't trigger any GH Actions build? Is it because I'm only a contributor?

[Munksgaard]

Perhaps we need to enable it?

[Munksgaard]

@laumann can you make me admin, or go take a look at the actions tab in settings yourself?

[Munksgaard]

Thank you for this, by the way, @phansch 🙂

[phansch]

Perhaps we need to enable it?

Yup, must be a permission/setting issue; It works on my fork: phansch#1

[phansch]

Alright, code-wise this is ready now. What needs to be done on the repo settings side would be:

1. Enabling GitHub Actions somewhere
2. Removing Appveyor from the build check requirements
3. Adding all the GitHub Actions builds to the build check requirements.
   This probably can only be done after they have all executed here once
   Maybe it's enough to close and re-open the PR to trigger the builds after 1) is done. That wouldn't require any pushes from my side.

[Munksgaard]

Thank you @phansch, I'll see what I can do.

[Manishearth]

IIRC for enabling github actions you just need to merge in a change to the workflows folder

[Manishearth]

@laumann I think you manually need to disable appveyor, i don't have access