>>> from gcloud import pubsub
>>> client = pubsub.Client(project = 'my_project')
>>> client.list_subscriptions(topic_name = 'my_topic')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/gcloud/pubsub/client.py", line 131, in list_subscriptions
    for resource in resp['subscriptions']]
  File "/usr/local/lib/python2.7/dist-packages/gcloud/pubsub/subscription.py", line 68, in from_api_repr
    topic_path = resource['topic']
TypeError: string indices must be integers