title: Using v-attr with attribute that contains colon 'xmlns:href' does not compile
body: <p>I am trying to use v-attr to add an attribute that contains a colon which is a delimiter for Vuejs key:value. It doesn't compile.</p>
  
  <pre><code>&lt;svg&gt;
      &lt;use xmlns:xlink="http://www.w3.org/1999/xlink" 
          v-attr="xmlns:href: '#' + iconID"&gt;&lt;/use&gt;
  &lt;/svg&gt;
  </code></pre>
  
  <p>I have also tried </p>
  
  <pre><code>&lt;svg class="lego-icon"&gt;
      &lt;use xmlns:xlink="http://www.w3.org/1999/xlink" 
          xmlns:href="#[[ iconID ]]"&gt;&lt;/use&gt;
  &lt;/svg&gt;
  </code></pre>
  
  <p>Which has similar results.</p>