circle: omit tests, etc from coverage

.circleci/config.yml

@@ -39,7 +39,7 @@ jobs:
             pip install coverage coveralls  # for https://coveralls.io/
 
             . local/bin/activate
-            python2 -m coverage run --source=. -m unittest discover -v
+            python2 -m coverage run --source=. --omit=appengine_config.py,local/\*,tests/\* -m unittest discover -v
             python2 -m coverage html -d /tmp/coverage_html
 
             # send coverage data to coveralls