title: How do I use react-helmet with netlify prerender?
body: <p>I'm trying to set up netlify prerendering with a react + react router + react helmet app. I'm trying to display the page title in the  tag and some open graph meta tags when a page is crawled.</p>
  
  <p>Here's the code calling react-helmet:</p>
  
  <pre><code>    &lt;Helmet&gt;
        &lt;title&gt;{entry.title} — Road Trip en Islande&lt;/title&gt;
        &lt;meta name="description" content="Nested component" /&gt;
        &lt;meta property="og:title" content={entry.title} /&gt;
        &lt;meta property="og:url" 
          content={`https://roadtrips.iwazaru.fr/entry/${entry.id}`} /&gt;
      &lt;/Helmet&gt;
  </code></pre>
  
  <p>from <a href="https://github.com/iwazaru/road-trips/blob/fb0d93af1d441b5f4378ee5d3e6f3bf0724b22e3/src/components/Entry/Entry.js" rel="nofollow noreferrer">https://github.com/iwazaru/road-trips/blob/fb0d93af1d441b5f4378ee5d3e6f3bf0724b22e3/src/components/Entry/Entry.js</a></p>
  
  <p>It does work in the browser without prerendering:
  <a href="https://roadtrips.iwazaru.fr/entry/S" rel="nofollow noreferrer">https://roadtrips.iwazaru.fr/entry/S</a></p>
  
  <p>It also works when prerending locally using <a href="https://github.com/netlify/prerender" rel="nofollow noreferrer">netlify prerender</a>, the correct title and open graph tags show up in the prerendered html.</p>
  
  <p>But when crawling the page with the facebook debugger, nothing that I put in react helmet seems to be prerendered although the rest of the page is correctly prerendered:
  <a href="https://developers.facebook.com/tools/debug/echo/?q=https%3A%2F%2Froadtrips.iwazaru.fr%2Fentry%2FS" rel="nofollow noreferrer">https://developers.facebook.com/tools/debug/echo/?q=https%3A%2F%2Froadtrips.iwazaru.fr%2Fentry%2FS</a></p>
  
  <p>Am I doing something wrong ?</p>