For `PUT` requests, `Response.url` is `undefined` for IE 11 and Edge <= 13

We saw this in production against IE 11, Edge 12, Edge 13, seems fixed on Edge 14 on Windows 7, 8.1, and Windows 10,

Here's a test case: https://github.com/michaelglass/repro-ie-put-bug/

The result of the Debug.log in the test case above yields:

{ status = { code = 200, message = "" }
, headers = Dict.fromList [("\ncontent-type","application/json; charset=utf-8")]
, url = <internal structure>
, body = "{\"updatedAt\":\"2018-04-05T08:48:49.587Z\"}" 
}

grabbing the output of the raw xhr request from toResponse(xhr) yields:

{
   0: <Unable to get property 'message' of undefined or null reference>,
   __proto__: { },
   DONE: 4,
   HEADERS_RECEIVED: 2,
   LOADING: 3,
   msCaching: "auto",
   onabort: null,
   onerror: null,
   onload: null,
   onloadend: null,
   onloadstart: null,
   onprogress: null,
   onreadystatechange: null,
   ontimeout: null,
   OPENED: 1,
   readyState: 4,
   response: "{"updatedAt":"2018-04-05T08:51:32.200Z"}",
   responseBody: <String expected>,
   responseText: "{"updatedAt":"2018-04-05T08:51:32.200Z"}",
   responseType: "text"
}

I couldn't get Ellie to work with IE11 but the bug reproduces fine from elm reactor.

(tagging @stoeffel as he helped here)

elm / http

For `PUT` requests, `Response.url` is `undefined` for IE 11 and Edge <= 13 #39