fix unittest import paths

BUG=None
TEST=unittests pass outside of sdk

Change-Id: I441acab6706278c37e7fa175830605f428654760
Reviewed-on: https://chromium-review.googlesource.com/216860
Reviewed-by: Alex Deymo <deymo@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/dep_tracker_unittest.py b/scripts/dep_tracker_unittest.py
index e340b11..64eadd8 100755
--- a/scripts/dep_tracker_unittest.py
+++ b/scripts/dep_tracker_unittest.py
@@ -6,7 +6,10 @@
 """Unit tests for dep_tracker.py."""
 
 import os
+import sys
 
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.realpath(__file__)),
+                                '..', '..'))
 from chromite.lib import cros_test_lib
 from chromite.lib import unittest_lib
 from chromite.scripts import dep_tracker