add explicit .toJSON() calls to ctx.toJSON()

lib/context.js

@@ -26,14 +26,19 @@ module.exports = {
   /**
    * Return JSON representation.
    *
+   * Here we explicitly invoke .toJSON() on each
+   * object, as iteration will otherwise fail due
+   * to the getters and cause utilities such as
+   * clone() to fail.
+   *
    * @return {Object}
    * @api public
    */
 
   toJSON: function(){
     return {
-      request: this.request,
-      response: this.response
+      request: this.request.toJSON(),
+      response: this.response.toJSON()
     }
   },