Split out keystone tenant client

Removes tenant client from identity client v2 into an own one.

Partially implements blueprint consistent-service-method-names

Change-Id: Ib164a108e2fea2c7c28d3a43b96c2881733bf34d
diff --git a/tempest/api/identity/v2/test_tenants.py b/tempest/api/identity/v2/test_tenants.py
index 1fcff8d..4e31557 100644
--- a/tempest/api/identity/v2/test_tenants.py
+++ b/tempest/api/identity/v2/test_tenants.py
@@ -26,7 +26,7 @@
     @test.idempotent_id('ecae2459-243d-4ba1-ad02-65f15dc82b78')
     def test_list_tenants_returns_only_authorized_tenants(self):
         alt_tenant_name = self.alt_manager.credentials.credentials.tenant_name
-        resp = self.non_admin_client.list_tenants()
+        resp = self.non_admin_tenants_client.list_tenants()
 
         # check that user can see only that tenants that he presents in so user
         # can successfully authenticate using his credentials and tenant name