Code review comment for lp://staging/~helipad-team/helipad/jenkins_coverage_pull_fix

I think it's ok for _get_artifact_urls to return an empty list.

Either enforce the 'SUCCESS' condition outside this _get_artifact_urls function or make it clear in the docstring that you won't return results for other builds.

This needs a test obviously :) , we can either do now or save for a testing-charette this week IMO.