[Travis] Emit all warnings during tests

.travis.yml

@@ -7,7 +7,7 @@ install:
   - pip install setuptools==24.3.1
   - pip install -r requirements.txt
 # command to run tests, e.g. python setup.py test
-script: "python manage.py test"
+script: "python -Wall manage.py test"
 addons:
   postgresql: "9.3"
 before_script: