Add cleanup for endpoint tests

In endpoint tests, cleanup is not handled in case
of any exception during creation and deletion of endpoint.

This commit adds the cleanup part for exception case too.

Change-Id: I6d9a1c01d3b7311e542dce88c11b21efb7759f26
diff --git a/tempest/api/identity/admin/v3/test_endpoints.py b/tempest/api/identity/admin/v3/test_endpoints.py
index 2538829..50cf258 100644
--- a/tempest/api/identity/admin/v3/test_endpoints.py
+++ b/tempest/api/identity/admin/v3/test_endpoints.py
@@ -80,6 +80,7 @@
                                                url=url, region=region,
                                                enabled=True)['endpoint']
 
+        self.setup_endpoints.append(endpoint)
         # Asserting Create Endpoint response body
         self.assertIn('id', endpoint)
         self.assertEqual(region, endpoint['region'])
@@ -102,6 +103,7 @@
 
         # Deleting the endpoint created in this method
         self.client.delete_endpoint(endpoint['id'])
+        self.setup_endpoints.remove(endpoint)
 
         # Checking whether endpoint is deleted successfully
         fetched_endpoints = self.client.list_endpoints()['endpoints']