[autotest] Update Repair and Verify to handle a testbed.

The repair and verify flow assumes the machine passed in is a host.
Both control segments now check to see if it's dealing with a testbed
and to run through a list of hosts and run the proper host methods to
ensure a successful verify/repair.

BUG=chromium:548739
TEST=Locally ran reverify/repair on testbed with shamu/angler/hammerhead
successfully.

Change-Id: Ib0ade22dd9e3d7496c083fe48b642ed4069eadd6
Reviewed-on: https://chromium-review.googlesource.com/318385
Commit-Ready: Kevin Cheng <kevcheng@chromium.org>
Tested-by: Kevin Cheng <kevcheng@chromium.org>
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Simran Basi <sbasi@chromium.org>
6 files changed