title: Decode HTML string
body: <p>How can I decode my html string from:</p>
  
  <pre><code>&lt;span&gt;Bj&amp;ouml;rn&lt;/span&gt;
  </code></pre>
  
  <p>to</p>
  
  <pre><code>&lt;span&gt;Björn&lt;/span&gt;
  </code></pre>
  
  <p>in Swift 3 ?</p>