Comment 2 for bug 1465307

Pretty sure this is the cause (from one of the "failed" units):

2015-06-15 15:51:51 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 15:51:51 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: worker stopped
2015-06-15 15:54:00 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 15:54:00 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: worker stopped
2015-06-15 15:54:24 WARNING juju.worker.uniter.operation leader.go:111 we should run a leader-deposed hook here, but we can't yet
2015-06-15 15:54:24 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 15:54:24 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: worker stopped
2015-06-15 15:54:48 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 15:54:48 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: worker stopped
2015-06-15 16:00:04 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 16:00:04 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: worker stopped
2015-06-15 17:08:00 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 17:08:00 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: worker stopped
2015-06-15 17:08:07 ERROR juju.worker.uniter.filter filter.go:137 tomb: dying
2015-06-15 17:08:07 ERROR juju.worker runner.go:219 exited "uniter": leadership failure: unable to make a leadership claim: no active lease manager