only bind to first /dev/loop, always unmount first

Signed-off-by: Simon Leung <leungs@us.ibm.com>
remove now-unused runners
pull etcd/nats/warden-linux/bbs setup into suite
loosen up kick interval to work around #76295518
fix timeout to account for longer interval
remove misleading flag

the rounds don't even start until the executor is up; maxRounds does not
come into play
hit router less hard
bump start timeouts to 5 seconds
bump executor start timeout

...to account for destroying containers on start. bump rep's timeout,
which depends on executor
tear file handling out of inigo server

* replace most occurrences with file server
* replace executor upload test with its own callback, which is a new
  helper that can perhaps replace the rest of inigo_server later
give executors separate cache so they blow up less
bump default consistently and eventually intervals
pull warden out, stop separately

also moved the container destroying logic into inigo, instead of
depending on warden's tricky SIGKILL semantics
added route check to stop check, minor cleanup

Signed-off-by: Stew Nickolas <nickolas@us.ibm.com>