This change adds a pre-run task to pull the fedora-toolbox images from
the registry to reduce the number of false positives caused by
'podman pull' failing to download them during the actual test.
Each section needs a separate playbook because they use different
versions of Fedora, and hence different default images.
https://github.com/containers/toolbox/pull/375
This adds several .yaml files that specify jobs (those in folder
playbooks) and one that serves as the main config (.zuul.yaml).
Tests and builds are currently executed on every change in PRs (ie.,
check and gating) and periodically (according to the documentation
this pipeline should be run at least once a day).
There are 4 tests in total:
1. 'ninja test' - does the same thing that Travis did
2. Fedora 30 - runs the system tests with current Podman and Toolbox
in Fedora 30
3. Fedora 31 - the same but for Fedora 31
4. Fedora Rawhide - the same but for Fedora Rawhide
https://github.com/containers/toolbox/issues/68
