title: React Native moment.locale does not work
body: <p>I am working with React Native version 0.45.1 and with moment version 2.18.1.</p>
  
  <p>I am trying to change the date according to the device local, but I always get the date in 'en-Us' locale.
  I can't import all of the locales as I saw in some solutions since I don't know the device locale in advance.
  (for example: <a href="https://github.com/moment/moment/issues/2962" rel="noreferrer">https://github.com/moment/moment/issues/2962</a>)</p>
  
  <p>any other options?</p>