handleUpgrades option support in ServerOptions interface

http://restify.com/#creating-a-server

In restify docs createServer method supports handleUpgrades parameter in ServerOptions object, but it's not present in the type's interface.

restify/restify.d.ts

@@ -110,6 +110,7 @@ declare module "restify" {
     version ?: string;
     responseTimeHeader ?: string;
     responseTimeFormatter ?: (durationInMilliseconds: number) => any;
+    handleUpgrades ?: boolean;
   }
 
   interface ClientOptions {