Pin grpcio at 0.13.1.

tseaver · tseaver · commit cbc24de1005e · 2016-05-11T17:47:11.000-04:00
0.14.0 causes google.pubsub.v1 to barf (see: https://github.com/googleapis/googleapis/issues/17).
diff --git a/setup.py b/setup.py
@@ -19,7 +19,7 @@
 ]
 
 GRPC_EXTRAS = [
-    'grpcio >= 0.13.1',
+    'grpcio == 0.13.1',
     'gax-google-pubsub-v1',
 ]
 
