docs: function endBuildStep(stepName, targetName, startTime) {
    const endTime = Date.now();
    const executionTime = new Date(endTime - startTime);
    const secs = executionTime.getSeconds();
    const ms = executionTime.getMilliseconds().toString();
    var timeString = '(';
    if (secs === 0) {
      timeString += ms + ' ms)';
    } else {
      timeString += secs + '.' + ms + ' s)';
    }
    if (!process.env.TRAVIS) {
      $$.util.log(
          stepName,
          $$.util.colors.cyan(targetName),
          $$.util.colors.green(timeString));
    }
  }