title: React router v4 active anchor link
body: <p>I got <strong><em>anchor</em></strong> <em>links</em> in my app. How do I make active style work if <code>anchor link</code> is active.</p>
  
  <pre><code>&lt;NavLink
    to="/#somewhere"
    activeClassName="selected"
  &gt;AnchorLink&lt;/NavLink&gt;
  </code></pre>