Update httplib2 from 0.10.3 to 0.11.3

requirements.txt

@@ -7,7 +7,7 @@ djangorestframework==3.7.7
 dockerflow==2018.2.1
 google-api-python-client==1.6.6
 gunicorn==19.7.1
-httplib2==0.10.3
+httplib2==0.11.3
 mock==2.0.0
 oauth2client==4.1.2
 psycopg2==2.7.4