Schema.$ref property in generated responses

The API definitions in the HAPI collection often show this problem:

```json
"responses": {
  "200": {
    "description":null,
     "schema":"#/definitions/Resource"
   }
} 
````

It should be

```json
"responses": {
  "200": {
    "description":"",
     "schema": {
        "$ref": "#/definitions/Resource"
      }
   }
} 
````
