message: Handles other common strings
diff: @@ -21,18 +21,21 @@ ERROR_401.status = 401;
  const ERROR_504 = new Error;
  ERROR_504.status = 504;
  -export default (err, req, res, next) => {
  +export default (err, _req, _res, next) => {
  let error;
  - if (contains(err.message, [
  + const errMessage = err.message && err.message.toLowerCase();
  +
  + if (contains(errMessage, [
  'not found', // Old-style errors
  "can't find", // New-style errors
  ])) error = ERROR_404;
  - if (contains(err.message, [
  + if (contains(errMessage, [
  'unauthorized', // Old-style errors
  'access denied', // Old-style errors
  'unable to', // New-style errors
  + 'requires sign in', // New-style errors
  ])) error = ERROR_401;
  if (err.timeout) {
  