Include nested group into destroy_service_spec

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

spec/services/groups/destroy_service_spec.rb

@@ -5,6 +5,7 @@ describe Groups::DestroyService, services: true do
 
   let!(:user)         { create(:user) }
   let!(:group)        { create(:group) }
+  let!(:nested_group) { create(:group, parent: group) }
   let!(:project)      { create(:project, namespace: group) }
   let!(:gitlab_shell) { Gitlab::Shell.new }
   let!(:remove_path)  { group.path + "+#{group.id}+deleted" }
@@ -20,6 +21,7 @@ describe Groups::DestroyService, services: true do
       end
 
       it { expect(Group.unscoped.all).not_to include(group) }
+      it { expect(Group.unscoped.all).not_to include(nested_group) }
       it { expect(Project.unscoped.all).not_to include(project) }
     end