function str2Bool(option) {
  if (typeof option === 'string') {
    if (option === 'true') {
      return true;
    } else if (option === 'false') {
      return false;
    }
  } else {
    return option;
  }
}
Function to convert `'true'` and `'false'` into `true` and `false`.
`commander` does not do the conversion automatically.
@param {any} option - a boolean type option
@returns {any} Usually `undefined`, `true` or `false`. if not then it is validated later on.