title: Add token in headers to display swagger UI
body: <p>I am stuck on something stupid : I want to display the documentation for each route with swagger only if I give a correct api-key. How can I achieve that? Where can I configure the headers when I try to load the UI?</p>
  
  <p>I tried that : </p>
  
  <pre><code>$('#input_apiKey').change(function() {
    var key = $('#input_apiKey')[0].value;
    if(key &amp;&amp; key.trim() != "") {
      swaggerUi.api.clientAuthorizations.add("key", new SwaggerClient.ApiKeyAuthorization("api_key", key, "header"));
    }
  })
  </code></pre>
  
  <p>But it doesn't appear in the request headers.</p>