title: Optional params with Play 2 and Swagger
body: <p>I'm trying to use Swagger to document a Play 2 REST API but <code>swagger-play2</code> doesn't seem to understand optional parameters defined with Scala's <code>Option</code> type - the normal way to make a param optional in Play 2:</p>
  
  <pre><code>GET /documents controllers.DocumentController.getDocuments(q: Option[String])
  </code></pre>
  
  <p>I want the <code>q</code> param to be optional. There is a matching annotated controller method with this <code>Option[String]</code> param. On startup I'm getting <code>UNKOWN TYPE</code> in the log and the json produced by api-docs breaks <code>swagger-ui</code>:</p>
  
  <pre><code>UNKNOWN TYPE: scala.Option
  [info] play - Application started (Dev)
  </code></pre>
  
  <p>Is there another way to specify an optional parameter in Play 2 and have Swagger understand it?</p>