Fix pubusb tests

Change-Id: I7dfe60b0f1240dc58a664968fd97ca5a8fa1109d

Author: Jon Wayne Parrott

samples/snippets/iam_test.py

@@ -21,12 +21,16 @@
 TEST_SUBSCRIPTION = 'iam-test-subscription'
 
 
-@pytest.fixture
+@pytest.fixture(scope='module')
 def test_topic():
     client = pubsub.Client()
     topic = client.topic(TEST_TOPIC)
-    topic.create()
+
+    if not topic.exists():
+        topic.create()
+
     yield topic
+
     if topic.exists():
         topic.delete()
 

samples/snippets/subscriber_test.py

@@ -22,12 +22,16 @@
 TEST_SUBSCRIPTION = 'subscription-test-subscription'
 
 
-@pytest.fixture
+@pytest.fixture(scope='module')
 def test_topic():
     client = pubsub.Client()
     topic = client.topic(TEST_TOPIC)
-    topic.create()
+
+    if not topic.exists():
+        topic.create()
+
     yield topic
+
     if topic.exists():
         topic.delete()