lib/utils/userStatsValidation.js/isValidObject
function isValidObject(key) {
  const isValid = VALID_TRACKING_OBJECTS.indexOf(key) !== -1;
  if (!isValid) {
    console.log(chalk.red('Tracking Error:'));
    console.log(`"${key}" is invalid tracking object. Must be one of`, VALID_TRACKING_OBJECTS);
  }
  return isValid;
}