Feature Request: Expose 429 Response headers

[i3149]

I'm frequently having to deal with 429 timeout response headers. If the swagger spec could be updated to expose the Retry-After header my code would be much cleaner. Something like:

 "429": {
            "description": "The request cannot be served due to the application’s rate limit having been exhausted for the resource.",
            "headers": {
                "Retry-After":
                        "type": "int",
                        "description": "The number of seconds the client should wait before retrying"
            },
            "schema": {
              "type": "object"
                message:
                   type: string
            }
}