Get new Credentials using a Refresh Token

[lbalmaceda]

Use the /oauth/token endpoint to get new Credentials given a valid refresh token.

Usage:

AuthenticationAPIClient client = new AuthenticationAPIClient(getAccount())
client.renewAuth("{refresh_token}")
   .addParameter("scope", "openid profile email") //Can specify more parameters
   .start(new BaseCallback<Credentials>() {
       @Override
       public void onSuccess(Credentials payload) { }

       @Override
       public void onFailure(AuthenticationException error) { }
   });