title: Can $on listener in a component listen for an $emit from mixin?
body: <p>I'd like my global mixin to broadcast data to various components. Trying to listen for the custom event from the created (or mounted) event inside the component doesn't seem to work. eg.</p>
  
  <p>in mixin ...</p>
  
  <pre><code>methods:  
     foo: function() {
       this.$emit('my-change','bar')
     } 
  </code></pre>
  
  <p>in component ...</p>
  
  <pre><code>created () {
    this.$on('my-change', function (e) {
      // do something 
    })
  }
  </code></pre>
  
  <p>Is this possible?</p>