const appAttachment = function (heroku, app, id, options = {}) {
  const headers = attachmentHeaders()
  return heroku.post('/actions/addon-attachments/resolve', {
    'headers': headers, 'body': {'app': app, 'addon_attachment': id, 'addon_service': options.addon_service}
  }).then(singularize('addon_attachment', options.namespace))