Add appengine workaround for oauth (GoogleCloudPlatform#628)

Author: jerjou

appengine/standard/firebase/firetactoe/appengine_config.py

@@ -1,4 +1,10 @@
+import os.path
+
 from google.appengine.ext import vendor
 
 # Add any libraries installed in the "lib" folder.
 vendor.add('lib')
+
+# Patch os.path.expanduser. This should be fixed in GAE
+# versions released after Nov 2016.
+os.path.expanduser = lambda path: path