Automated testing

[kwk]

This is an early attempt to solve what we've discussed in the chat.

1. Once we find a chroot that has all succeeded builds we should run the tests on testing-farm for that chroot. Before starting the tests we should add the label in_testing/fedora-rawhide-x86_64 (could be any other chroot) to the issue. The CI job runs on a schedule and this signals the next run that even though a chroot only contains succeeded builds, we should not trigger tests but keep calm instead.
2. Once the testing farm results are in, we remove the in_testing/fedora-rawhide-x86_64 label and add tested_on/fedora-rawhide-x86_64 or failed_on/fedora-rawhide-x86_64 to the issue. This will also be interpreted by the CI to not kick of any more tests.
3. Once we have only tested_on/fedora-rawhide-x86_64 respectively for all chroots, we can consider this build tested and worth promoting.

TODOs

• Create in_testing/<chroot> labels
• Create tested_on/<chroot> labels
• Create failed_on/<chroot> labels
• Don't start testing if in progress, or already tested (result is irrelevant)
• Kick off testing on testing-farm
• Kick off promotion