use an importlib that doesn't blow up on python 2.7 which you shouldn't be using anyway

requirements/prod.txt

@@ -45,7 +45,7 @@ gunicorn==0.15.0
 hera==0.1.2
 html5lib==0.90
 httplib2==0.7.6
-importlib==1.0.2
+importlib-no-failure==1.0.2
 kombu==2.1.2
 metlog-py==0.9.10
 metlog-cef==0.2