title: Omit null values in json response from Nancy FX
body: <p>I am trying to create a REST service using Nancy FX in a C# environment. I can easily do a Response.AsJson and it all looks good. But I want the response to omit any properties that are null.</p>
  
  <p>I have not been able to figure out how to do this yet.</p>
  
  <p>Could someone point to me towards a help document or a blog post somewhere, that explains how to do this.</p>
  
  <p>Thanks,
  JP</p>