Why does project-service require id on the CLI? #191

Using gitlab project-service get --project-id 111 --service-name=slack returns with an error that --id is a required parameter but when using that parameter with the correct ID, GitLab responds with a 404.

When using the library and calling g.project_services.get(service_name='slack', project_id=project.id) there is no id required and we get the correct result. Any ideas why?