title: Select `optgroup` in vue 1.x
body: <p>In earlier versions of <code>vue.js</code> you could create a dynamic select list using <code>optgroups</code> like <a href="http://jsfiddle.net/caLg94ka/1/" rel="nofollow">this</a>.</p>
  
  <p>In the newer versions of vue the docs show using <code>v-for</code> in the options, and it appears they no longer support <code>optgroups</code>. Is there a workaround for this?</p>