adds cherry-picking to the nightly revert checker

BUG=chromium:1085465
TEST=nightly_revert_checker_test.py

Change-Id: I8069bb3f6ca8d07f54568b85373910a192d11ea5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2680123
Auto-Submit: Christopher Di Bella <cjdb@google.com>
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
5 files changed