Operation-level servers override

Hi! At this moment i cannot get 'servers' to work under operation level to specify separate servers to specific endpoint:

```
    "/ApiKey.GetList": {
      "servers": [{
        "url": "http://localhost:80/",
        "description": "local api-keys instance"
      }],
      "post": {
        <or even here>
         ....
```

Is there a way it can be done?