[sepia] PSA: developer playground nodes can schedule runs to teuthology

See: https://wiki.sepia.ceph.com/doku.php?id=devplayground#teuthology_scheduling Scheduling teuthology runs on these nodes is generally 30-50% faster than teuthology.front. Note: you generally can only kill runs on teuthology.front (because you need to kill test processes running there). -- Patrick Donnelly, Ph.D. He / Him / His Red Hat Partner Engineer IBM, Inc. GPG: 19F28A586F808C2402351B93C3301A3E258DD79D