Update access token for multi-user app.

[imazhar102]

This may not be an issue or may be required to improve reusability of code, shouldn't there be a way to update the access_token? I've many users using the same Uber back end and upon hitting the Node js app I need to override the Uber object's access token. This will help anybody accessing the system to get their information from the APIs and won't be restricted to single User.