factory_flow: Add test_factory_flow tool.

The tool enables automated factory flow testing using YAML-based config files.

BUG=chrome-os-partner:26795
TEST=manually test on my DUT

Change-Id: I12ee6b94f4f595b727478a7139b091bce7706f01
Reviewed-on: https://chromium-review.googlesource.com/196181
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Queue: Ricky Liang <jcliang@chromium.org>
Tested-by: Ricky Liang <jcliang@chromium.org>
2 files changed