title: mat-chip select event emitter not firing?
body: <p>Plunkr: <a href="http://plnkr.co/edit/y4e4jS89gOxRKQOyUW2r?p=preview" rel="noreferrer">http://plnkr.co/edit/y4e4jS89gOxRKQOyUW2r?p=preview</a></p>
  
  <p>I'm using the selectionChange @Output on a mat-chip to see the resulting behavior of chip selection but it seems that the eventEmitter isn't firing on chip selection?</p>
  
  <p>.html:</p>
  
  <pre><code>&lt;mat-chip-list&gt;
    &lt;mat-chip (selectionChange)="changeSelected($event)"&gt;Papadum&lt;/mat-chip&gt;
    &lt;mat-chip (selectionChange)="changeSelected($event)"&gt;Naan&lt;/mat-chip&gt;
    &lt;mat-chip (selectionChange)="changeSelected($event)"&gt;Dal&lt;/mat-chip&gt;
  &lt;/mat-chip-list&gt;
  
  &lt;p&gt;Currently Selected: {{selected}}&lt;/p&gt;
  </code></pre>
  
  <p>.ts:</p>
  
  <pre><code>selected: string;
  
  changeSelected(e) {
    console.log(e);
    this.selected = e.value;
  }
  </code></pre>
  
  <p>In this case, no event is emitted at all on click selection. Is this something that is still in development, or does selection mean something different from what I am thinking of?</p>