Fix newline at end of test_mqtt_client.py

Author: tyeth

tests/test_mqtt_client.py

@@ -243,4 +243,4 @@ def test_receive_with_invalid_feed_key(self):
         """Test that receive() raises TypeError with invalid feed key."""
         client = MQTTClient('testuser', 'testkey')
         with self.assertRaises(TypeError):
-            client.receive('test@feed')
+            client.receive('test@feed')