Add sample control file to demonstrate passing of specific APs.

 - refactor control template into a Python class
 - support both ChaosOpen and ChaosPSK tests

BUG=chromium:236421
TEST=Manual (ran test using control.debug for both ChaosOpen and ChaosPSK and
             verified tests completed successfully)

Change-Id: I477049c025a74f96c15c445e28dce0ef73dbd05a
Reviewed-on: https://gerrit.chromium.org/gerrit/50239
Reviewed-by: Kris Rambish <krisr@chromium.org>
Tested-by: Tan Gao <tgao@chromium.org>
6 files changed