Drop AppVeyor

[ptrdom]

With CI being already migrated to GitHub Actions, keeping AppVeyor seems unnecessary. Less CI scripts to maintain. Since GitHub Actions require approval for first time contributors and AppVeyor did not, maybe it would be good to reconsider loosening this rule for GitHub Actions in this repository.

[sjrd]

The point of the AppVeyor build is to test on Windows. If we remove AppVeyor, we must add a Windows build to the GitHub Actions CI.

[ptrdom]

GitHub has Windows machines available for running Actions, with matrix it is relatively easy to setup, I will add it to this PR.

[sjrd]

The Windows build doesn't seem to test anything. It completed in 1 minute without doing much of anything. By comparison, the Linux build takes more than 15 minutes.

[ptrdom]

Really strange. Posted in community about it - https://git.luolix.topmunity/t/windows-runner-not-executing-sbt-commands/250507.

[armanbilge]

Note that olafurpg/setup-scala action is effectively deprecated. It might not be doing the right things.

• Archive this repo? olafurpg/setup-scala#49

[ptrdom]

@armanbilge You were right, many thanks! One test does fail, and the runner seems quite slow, but the same test fails on my Windows machine too. AppVeyor tests run on older WIndows Server version, so that must be related. Will look into that next.

[ptrdom]

Looks nasty:

Error: [error] (server / Compile / doc) java.net.URISyntaxException: Illegal character in path at index 53: [https://docs.oracle.com/en/java/javase/11/docs/api/C:\Users\runneradmin\AppData\Local\Coursier\cache\jvm\adopt@1.11.0-11\jmods\java.base/java/lang/Class.html](https://docs.oracle.com/en/java/javase/11/docs/api/C:/Users/runneradmin/AppData/Local/Coursier/cache/jvm/adopt@1.11.0-11/jmods/java.base/java/lang/Class.html)

https://github.com/scalacenter/scalajs-bundler/runs/6439309039?check_suite_focus=true#step:8:694

[ptrdom]

Looks related to scala/bug#11955.

[ptrdom]

@sjrd Does this look mergeable to you?

[sjrd]

LGTM. Could you squash everything in a single commit with a clean commit message, please? Please also explain the change of Scala version in the test.

[ptrdom]

@sjrd Done!