title: How to assign a relationship in Ember Data when it doesn't have an ID yet?
body: <p>I have a new team member, which belongs in a team but the member doesn’t have an ID yet because the record hasn't been send to the server yet how do I tell the team that the member belongs in the team and let it appear in the team list before sending the team member to the server and assigning a unique ID to the member.</p>