Trying to do offline data with ember-data

models.js

import DS from 'ember-data';

var Checkin = DS.Model.extend({
  shout: DS.attr('string'),
  user: DS.belongsTo('user'),
  venue: DS.belongsTo('venue'),
  createdAt: DS.attr('date')
});

var User = DS.Model.extend({
    firstName: attr('string'),
    lastName: attr('string'),
    homeCity: attr('string'),
    gender: attr('string'),
    bio: attr('string'),
    
    checkins: DS.hasMany('checkin'),
    accessToken: attr('string'),

    lastUpdated: attr('date')
});

var Venue = DS.Model.extend({
  checkins: DS.hasMany('checkin'),
  name: attr('string')
});

timeline_route.js

data.response.recent.forEach(function(c) {
  var user = controller.store.createRecord('user', {
    id: c.user.id,
    firstName: c.user.firstName,
    lastName: c.user.lastName,
    bio: c.user.bio
  });
  user.save();

  var venue = controller.store.createRecord('venue', {
    id: c.venue.id,
    name: c.venue.name
  });
  venue.save();

  var checkin = controller.store.createRecord('checkin', {
    id: c.id,
    user: user,
    venue: venue,
    createdAt: moment.unix(c.createdAt)._d,
    isRecent: true
  });

  checkin.save();
});