Fix analyzer errors in the http_parser web socket test.

pkg/http_parser/test/web_socket_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library http_parser.web_socket_test;
 
 import 'dart:io';
 
 import 'package:http_parser/http_parser.dart';
 import 'package:unittest/unittest.dart';
@@ skipping 25 matching lines @@
         var n = 0;
         return webSocket.listen((message) {
           if (n == 0) {
             expect(message, equals("hello!"));
             webSocket.add("ping");
           } else if (n == 1) {
             expect(message, equals("pong"));
             webSocket.close();
             server.close();
           } else {
-            expect(false, reason: "Only expected two messages.");
+            fail("Only expected two messages.");
           }
           n++;
         }).asFuture();
       });
     });
   });
 
   test("a server can communicate with a WebSocket client", () {
     return HttpServer.bind("localhost", 0).then((server) {
       server.listen((request) {
@@ skipping 21 matching lines @@
         var n = 0;
         return webSocket.listen((message) {
           if (n == 0) {
             expect(message, equals("hello!"));
             webSocket.add("ping");
           } else if (n == 1) {
             expect(message, equals("pong"));
             webSocket.close();
             server.close();
           } else {
-            expect(false, reason: "Only expected two messages.");
+            fail("Only expected two messages.");
           }
           n++;
         }).asFuture();
       });
     });
   });
 }