PR testing: when the build is ready, comment the link to access the test site
Currently, when a PR is opened on github.com/civicrm/civicrm-{core,packages}/,
- Jenkins runs the PR tests
- as part of the PR tests, a test site is available on test-ubu1204-5 for a few days
- the URL & credentials for that site are available deep in the Jenkins build logs.
It would be nice if we could comment that URL on the github PR automatically, so that people do not need to hunt for the URL (if the build is successful).