function dateFormatISO(dt) {
  return dt.format('YYYY-MM-DDTHH:mm:ss[Z]');
}
Formats a moment() object to: YYYY-MM-DDTHH:mm:ssZ
Example: 2017-07-13T13:31:13Z

@param {Object} dt The moment object to export.
@return {string} YYYY-MM-DDTHH:mm:ssZ.