auth.js

var email = "email";
var password = "password";
var data = {email: email, password: password};

Application.ref.createUser(data, function(error){
  if(! error ){
    ref.authWithPassword(data, function(error, authData){
      if( ! error && authData ){
        data.id = authData.uid;
        var user = self.store.createRecord('user', data);
        user.save();
      }
    })
  }
})