* Switch healthcheck interval/timeout from 30s/3s to 60s/10s.
30s interval is arguably overkill, and 3s timeout is definitely too short
for lower end machines.
* Use HEALTHCHECK CMD exec form to avoid superfluous `sh` invocations.
* Add `--silent --show-error` flags to curl call to avoid progress meter being
shown in healthcheck logs.
Jeremy Lin
bbb0484d03