Action helper method "on" doesn't work

components.my-test.js

import Ember from 'ember';

export default Ember.Component.extend({
	actions: {
    testAction() {
      Ember.Logger.info("MouseDown event has been caught!");
    }
  }
});

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{my-test}}
<br>
<br>

templates.components.my-test.hbs

<button {{action "testAction" on="mouse-down"}}>Push me</button>

twiddle.json

{
  "version": "0.4.8",
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.4/jquery.js",
    "ember": "http://builds.emberjs.com/release/ember.debug.js",
    "ember-template-compiler": "http://builds.emberjs.com/release/ember-template-compiler.js"
  }
}