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';