It looks like this has come up in the past (#82). I'm not 100% clear on what the resolution was, but it would be great if collaborators could add a label/comment to a PR to trigger a full CI run in Jenkins. I have a preference toward a label over a comment because a comment generates an email/notification, and issue labeling is restricted to trusted collaborators. This would imply the "Certify Safe" checkbox in Jenkins.

I think the following workflow would allow collaborators to avoid Jenkins completely in a lot of cases:

• A new PR is opened.
• Collaborator reviews the PR to certify its safety.
• Collaborator adds a specific label to the PR.
• Bot notices the label, removes the label, and starts a full CI run.
• Bot posts a comment to the PR containing the CI run URL.