Batch: only print statuses with >0 jobs
To avoid flooding the screens with all the empty statuses, i.e. going from
INFO:bamboo.batch:[ 13:52:12 :: 0 PENDING, 16 RUNNING, 158 COMPLETED, 0 FAILED, 0 COMPLETING, 0 CONFIGURING, 0 CANCELLED, 0 BOOT_FAIL, 0 NODE_FAIL, 0 PREEMPTED, 0 RESIZING, 0 SUSPENDED, 0 TIMEOUT, 0 OUT_OF_MEMORY, 0 REQUEUED, 0 unknown / 174 Total ]
to
INFO:bamboo.batch:[ 10:09:26 :: 146 RUNNING, 28 COMPLETED / 174 Total ]