pin six for google api

Author: Chris M

setup.py

@@ -64,7 +64,7 @@ def _DetectBadness():
 install_requires = [
     'httplib2>=0.8',
     'oauth2client>=1.4.6,<=3.0.0',
-    'six>=1.6.1',
+    'six>=1.6.1,<=1.10.0',
     'uritemplate>=0.6',
 ]