BUG in Ember nested component - EMBER 2.10.0-beta.2

components.parent-component.child-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

components.parent-component.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to ember-cli@2.10.0-beta.2</h1>
<br>
<br>
{{parent-component}}
{{parent-component.child-component}}  -> Not showing
{{outlet}}
<br>
<br>

templates.components.parent-component.child-component.hbs

child component 
{{yield}}

templates.components.parent-component.hbs

parento component
{{yield}}

twiddle.json

{
  "version": "0.10.6",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "alpha",
    "ember-data": "2.9.0",
    "ember-template-compiler": "alpha",
    "ember-testing": "alpha"
  },
  "addons": {}
}