Fix resource leaks in EndPointGroupsTest

Test cases were creating services at the test case
scope and not add them to addCleanup method.

Change-Id: I390f9e013930477f32c537191adbef37e1b4dd1c
diff --git a/tempest/api/identity/admin/v3/test_endpoint_groups.py b/tempest/api/identity/admin/v3/test_endpoint_groups.py
index 625568d..7d85dc9 100644
--- a/tempest/api/identity/admin/v3/test_endpoint_groups.py
+++ b/tempest/api/identity/admin/v3/test_endpoint_groups.py
@@ -69,6 +69,7 @@
     @decorators.idempotent_id('7c69e7a1-f865-402d-a2ea-44493017315a')
     def test_create_list_show_check_delete_endpoint_group(self):
         service_id = self._create_service()
+        self.addCleanup(self.services_client.delete_service, service_id)
         name = data_utils.rand_name('service_group')
         description = data_utils.rand_name('description')
         filters = {'service_id': service_id}
@@ -129,6 +130,7 @@
         # Creating an endpoint group so as to check update endpoint group
         # with new values
         service1_id = self._create_service()
+        self.addCleanup(self.services_client.delete_service, service1_id)
         name = data_utils.rand_name('service_group')
         description = data_utils.rand_name('description')
         filters = {'service_id': service1_id}