Bump src/hm9000

HM9000 is not longer a singleton

Bump cloudfoundry/hm-workspace:
  Onsi Fakhouri:
     more work on travis flakiness ( Travis Success: https://travis-ci.org/cloudfoundry/hm-workspace/builds/15554612 )
     make tests less flakey? ( Travis Failed: https://travis-ci.org/cloudfoundry/hm-workspace/builds/15554067 )
     Merge branch 'master' of https://github.com/cloudfoundry/hm-workspace ( Travis Failed: https://travis-ci.org/cloudfoundry/hm-workspace/builds/15541773 )
     HM9000 is no longer a singleton ( Travis Unknown )
     fix null json array issue, bump testing framework ( Travis Success: https://travis-ci.org/cloudfoundry/hm-workspace/builds/15410765 )
warden: don't destroy containers on startup

We're using the snapshot feature again, so this is counterproductive.

Old containers should be destroyed via the grace period if no one's
actually talking to them.
update drain script to add snapshotting

If the job is shutting down, execute the deterministic evacuation
policy.

Otherwise, send USR1 once, and wait for all staging tasks to complete.
After that, send USR2 to Warden, and kill -9 the DEA. No evacuation
is performed. Both jobs will come up and repopulate their state via
their respective snapshot loading mechanisms.

[finishes #57361124]

Signed-off-by: Onsi Fakhouri <onsi@pivotallabs.com>
Merge remote-tracking branch 'upstream/master'