Different serverTokenEndpoint for login and registration

I'm using ember-simple-auth for logging in a user which is working fine. For logging a user in, I've to ping this endpoint: /auth/sign_in.

However, for registering a new user, I've to ping a different endpoint: /auth.

If I'm trying to use the ember-simple-auth for also registering (as instructed in this blog: http://ift.tt/290uXll), I'm facing the issue that Ember is pinging the same endpoint (as specified in the serverTokenEndpoint).

How can I register a new user using ember-simple-auth?