You shouldn't have to do to many checks and each key translation.
Keep in mind this method can be called a very high number of times!
```
I'd suggest to cache getPreferedLocales(true) in a global,
and pass it from exports.get:
const preferedLocales = getPreferedLocales(true);
function get(k, n, locales) {
  let locale = locales.shift();
  ...
}
exports.get = function(k, n) get(k, n, preferedLocales);
```