[0.3.0] belongs_to relation issue

mirage.config.js

export default function() {
  //window.server = this;
  this.get('users');
};

mirage.factories.user.js

import { Factory, faker, trait } from 'ember-cli-mirage';

export default Factory.extend({
  name() {
    return faker.name.findName();
  },
  withChildrens: trait({
    afterCreate(parent, server) {
      server.create('user', { parent, name: 'first child' });
      server.create('user', { parent, name: 'second child' });
      server.create('user', { parent, name: 'third child' });
    }
  })
});

mirage.models.user.js

import { Model, belongsTo, hasMany } from 'ember-cli-mirage';

export default Model.extend({
  parent: belongsTo('user', { inverse: 'children' }),
  children: hasMany('user', { inverse: 'parent' })
});

mirage.scenarios.default.js

export default function(server) {  
  server.create('user', 'withChildrens');
}

mirage.serializers.application.js

import { JSONAPISerializer } from 'ember-cli-mirage';

export default JSONAPISerializer.extend({
});

models.user.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  name: attr(),
  parent: belongsTo('user', { inverse: 'children' }),
  children: hasMany('user', { inverse: 'parent' })
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return this.store.findAll('user');
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

h1 {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  text-shadow: none;
  background: #2e4068;
  color: white;
  padding: 20px;
  margin: 0;
  text-transform: uppercase;
}

p {
  font-weight: normal;
}

.pa4 {
  padding: 20px;
}

templates.application.hbs

<h1>Mirage boilerplate</h1>

<div class='pa4'>
  {{#each model as |user|}}
  <p>
    I'am <strong>{{user.name}}</strong> 
    {{#if user.parent }}
      child of: {{user.parent.name}}
    {{/if}}
    </p>
  {{/each}}
</div>

twiddle.json

{
  "version": "0.12.1",
  "ENV": {
    "ember-cli-mirage": {
      "enabled": true
    }
  },
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1",
    "ember-cli-mirage": "0.3.0"
  }
}