René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Error passing 'fields' to pubsub GET API for subscription","articleBody":"```\n$ tox -e regression --notest\nGLOB sdist-make: /home/tseaver/projects/agendaless/Google/src/gcloud-python/setup.py\nregression inst-nodeps: /home/tseaver/projects/agendaless/Google/src/gcloud-python/.tox/dist/gcloud-0.4.3.zip\n___________________________________ summary ____________________________________\n  regression: skipped tests\n  congratulations :)\n$ .tox/regression/bin/python regression/run_regression.py --package=pubsub\ntest_create_subscription (pubsub.TestPubsub) ... ERROR\ntest_create_topic (pubsub.TestPubsub) ... ok\ntest_list_subscriptions (pubsub.TestPubsub) ... ok\ntest_list_topics (pubsub.TestPubsub) ... ok\ntest_message_pull_mode_e2e (pubsub.TestPubsub) ... ERROR\n\nERROR: test_create_subscription (pubsub.TestPubsub)\n----------------------------------------------------------------------\nTraceback (most recent call last):\n  File \"/home/tseaver/projects/agendaless/Google/src/gcloud-python/regression/pubsub.py\", line 74, in test_create_subscription\n    self.assertFalse(subscription.exists())\n  File \"/home/tseaver/projects/agendaless/Google/src/gcloud-python/.tox/regression/lib/python2.7/site-packages/gcloud/pubsub/subscription.py\", line 112, in exists\n    query_params={'fields': 'name'})\n  File \"/home/tseaver/projects/agendaless/Google/src/gcloud-python/.tox/regression/lib/python2.7/site-packages/gcloud/connection.py\", line 293, in api_request\n    raise make_exception(response, content)\ngcloud.exceptions.BadRequest: 400 Invalid JSON payload received. Unknown name \"fields\": Cannot bind query parameter.\n```\n\nI omitted a similar failure in another test:  both are for a call to `subscription.exists()` where the expected value is False.\n\n@dhermes this is the one I was working around in #794 \n\n@jgeewax maybe tag w/ \"google bug\"?\n","author":{"url":"https://github.com/tseaver","@type":"Person","name":"tseaver"},"datePublished":"2015-04-06T20:23:01.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":19},"url":"https://github.com/799/google-cloud-python/issues/799"}