Auto-update dependencies. (GoogleCloudPlatform#1375)

Author: dpebot

testing/requirements.txt

@@ -13,5 +13,5 @@ WebTest==2.0.29
 webapp2==2.5.2
 google-api-python-client==1.6.5
 google-cloud-core==0.28.0
-gcp-devrel-py-tools==0.0.12
+gcp-devrel-py-tools==0.0.13
 flask==0.12.2