title: Validation of Express request based on Swagger YAML
body: <p>Is out there a node module for validation of the schema/values provided in Express req object, based on Swagger YAML schema definition for that request?</p>
  
  <p>Let's say this is relevant part of the YAML:</p>
  
  <pre><code>  /books/{genre}:
      get:
      parameters:
        - name: genre
          in: path
          required: true
          type: string
        - name: size
          in: query
          required: false
          type: number
  </code></pre>
  
  <p>A req object derived from the following request should pass validation:</p>
  
  <pre><code>GET /books/sci-fi          
  GET /books/thriller?size=5
  </code></pre>
  
  <p>And this one should fail:</p>
  
  <pre><code>GET /books/12
  </code></pre>