Stop using hpcloud az1-az3 in favor of region-b

Remove hpcloud 1.0 from all jenkins masters, and set max-servers to 0.
Wait until existing nodes have exhausted before removing the image defs.

Change-Id: If153908e7489da3cb9542489c48de71d8b5c9f35
Merge "Stop using hpcloud az1-az3 in favor of region-b"