ignore paths in licenses/ dirs for style/etc... checks

We don't want to enforce copyright/license/whitespace/etc... issues on
license files themselves as we often obtain these from some other place
and the content should be preserved exactly.

BUG=chromium:323243
TEST=`./pre-upload_unittest.py` passes
TEST=uploading a license file in chromiumos-overlay/ no longer triggers checks

Change-Id: Iaa9c08701472cafc14e660dd48147c87cb74682b
Reviewed-on: https://chromium-review.googlesource.com/188580
Reviewed-by: Yu-Ju Hong <yjhong@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed