Job configs are stored in YAML files in hack/jenkins/job-configs in the
format used by Jenkins Job Builder. A docker container running on
Jenkins fetches job configs every fifteen minutes and updates Jenkins.
And a config description. This doesn't yet have much - first want to
make sure I can do the build job. Next I'll submit the e2e script with
its twiddles and switch those over. (After going to 3 e2es, I think
it's finally time for version control.)