Split out Neutron subnets client

Splitting out a subnets client for Neutron.

Partially implements blueprint consistent-service-method-names

Change-Id: I52c9d099b97540440fa98343c736b894d130a07e
diff --git a/tempest/clients.py b/tempest/clients.py
index cffdc3f..efb6fea 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -108,6 +108,7 @@
     MessagingClient
 from tempest.services.network.json.network_client import NetworkClient
 from tempest.services.network.json.networks_client import NetworksClient
+from tempest.services.network.json.subnets_client import SubnetsClient
 from tempest.services.object_storage.account_client import AccountClient
 from tempest.services.object_storage.container_client import ContainerClient
 from tempest.services.object_storage.object_client import ObjectClient
@@ -205,6 +206,14 @@
             build_interval=CONF.network.build_interval,
             build_timeout=CONF.network.build_timeout,
             **self.default_params)
+        self.subnets_client = SubnetsClient(
+            self.auth_provider,
+            CONF.network.catalog_type,
+            CONF.network.region or CONF.identity.region,
+            endpoint_type=CONF.network.endpoint_type,
+            build_interval=CONF.network.build_interval,
+            build_timeout=CONF.network.build_timeout,
+            **self.default_params)
         self.messaging_client = MessagingClient(
             self.auth_provider,
             CONF.messaging.catalog_type,