Fix name "Quantum" to "Neutron" in comment

This changes "Quantum" => "Neutron" in comment of test_floating_ips.py

Change-Id: I92157f9f134aa3b0d4a5e850f8468f2b71fa1b2d
diff --git a/tempest/api/network/test_floating_ips.py b/tempest/api/network/test_floating_ips.py
index f0923d2..4b4a4e2 100644
--- a/tempest/api/network/test_floating_ips.py
+++ b/tempest/api/network/test_floating_ips.py
@@ -25,7 +25,7 @@
 
 class FloatingIPTestJSON(base.BaseNetworkTest):
     """
-    Tests the following operations in the Quantum API using the REST client for
+    Tests the following operations in the Neutron API using the REST client for
     Neutron:
 
         Create a Floating IP