Remove HTTP 1223 handling

The 1223 error was fixed in IE 10. See https://blogs.msdn.microsoft.com/ieinternals/2012/03/01/internet-explorer-10-consumer-preview-minor-changes-list/

lib/adapters/xhr.js

@@ -49,9 +49,8 @@ module.exports = function xhrAdapter(config) {
  var responseData = !config.responseType || config.responseType === 'text' ? request.responseText : request.response;
  var response = {
  data: responseData,
- // IE sends 1223 instead of 204 (https://github.com/axios/axios/issues/201)
- status: request.status === 1223 ? 204 : request.status,
- statusText: request.status === 1223 ? 'No Content' : request.statusText,
+ status: request.status,
+ statusText: request.statusText,
  headers: responseHeaders,
  config: config,
  request: request

test/specs/requests.spec.js

@@ -220,28 +220,6 @@ describe('requests', function () {
  });
  });
 
- // https://github.com/axios/axios/issues/201
- it('should fix IE no content error', function (done) {
- var response;
-
- axios('/foo').then(function (res) {
- response = res
- });
-
- getAjaxRequest().then(function (request) {
- request.respondWith({
- status: 1223,
- statusText: 'Unknown'
- });
-
- setTimeout(function () {
- expect(response.status).toEqual(204);
- expect(response.statusText).toEqual('No Content');
- done();
- }, 100);
- });
- });
-
  it('should allow overriding Content-Type header case-insensitive', function (done) {
  var response;
  var contentType = 'application/vnd.myapp.type+json';