run unittests as part of upload

These unittests are fast (<100ms), so run them automatically when
uploading in this dir.

BUG=chromium:340036
TEST=`repo upload` still works in this dir

Change-Id: Ie12d0fbfa611047b244d23a5183fe3513788d114
Reviewed-on: https://chromium-review.googlesource.com/185132
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/PRESUBMIT.cfg b/PRESUBMIT.cfg
index 5e25fff..af59bca 100644
--- a/PRESUBMIT.cfg
+++ b/PRESUBMIT.cfg
@@ -1,2 +1,3 @@
 [Hook Scripts]
-hook0=../../chromite/bin/cros lint ${PRESUBMIT_FILES}
+hook0 = ../../chromite/bin/cros lint ${PRESUBMIT_FILES}
+hook1 = ./pre-upload_unittest.py