[moblab] Initial Version of moblab_RunSuite test.

Updated moblab_host with the following functions:
* find_and_add_duts to find DUTs on the subnet and add them if they
  are not already in the AFE.
* run_as_moblab function to run commands as the moblab user.
* wait_afe_up function to gate tasks that rely on the AFE being up.

Added a new MoblabTest class that handles basic Moblab test tasks that
will be common to Moblab tests:
* Installing a boto file.
* Setting the image_storage_server to use.

Added the initial version of Moblab_RunSuite test which runs a suite
on a Moblab.
* Currently just has one control file that kicks off the smoke suite.

BUG=chromium:388462
TEST=Ran via test_that.

Change-Id: I697f5b94afc88633e213d3b35b53f8f7d5a6240b
Reviewed-on: https://chromium-review.googlesource.com/210592
Tested-by: Simran Basi <sbasi@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
Commit-Queue: Simran Basi <sbasi@chromium.org>
4 files changed