Add a word "Test" to metering test classes

All test class except metering test classes contains "Test" in their
names. This patch adds the word to metering test classes for clarifying
the test classes.

Change-Id: I8d42d73464a94f5229ff7065404bbf3b402c75c7
diff --git a/tempest/api/network/test_metering_extensions.py b/tempest/api/network/test_metering_extensions.py
index daf9948..4df7812 100644
--- a/tempest/api/network/test_metering_extensions.py
+++ b/tempest/api/network/test_metering_extensions.py
@@ -23,7 +23,7 @@
 LOG = logging.getLogger(__name__)
 
 
-class MeteringJSON(base.BaseAdminNetworkTest):
+class MeteringTestJSON(base.BaseAdminNetworkTest):
     _interface = 'json'
 
     """
@@ -36,7 +36,7 @@
 
     @classmethod
     def resource_setup(cls):
-        super(MeteringJSON, cls).resource_setup()
+        super(MeteringTestJSON, cls).resource_setup()
         if not test.is_extension_enabled('metering', 'network'):
             msg = "metering extension not enabled."
             raise cls.skipException(msg)
@@ -145,5 +145,5 @@
         self.assertFalse(metering_label_rule['excluded'])
 
 
-class MeteringIpV6JSON(MeteringJSON):
+class MeteringIpV6TestJSON(MeteringTestJSON):
     _ip_version = 6