pkg/scheduled_test: fix analyzer hints

test/scheduled_stream/stream_matcher_test.dart

 // Copyright (c) 2013, 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 scheduled_test.stream_matcher_test;
 
 import 'dart:async';
 
 import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:scheduled_test/src/utils.dart';
 
-import 'package:metatest/metatest.dart';
 import '../utils.dart';
 
 /// Returns a [ScheduledStream] that asynchronously emits the numbers 1 through
 /// 5 and then closes.
 ScheduledStream createStream() {
   var controller = new StreamController();
   var stream = new ScheduledStream(controller.stream);
 
   var future = pumpEventQueue();
   for (var i = 1; i <= 5; i++) {
@@ skipping 285 matching lines @@
     expect(error.message, equals(
         "Expected: is done\n"
         " Emitted: * 1\n"
         "          * 2\n"
         "          * 3\n"
         "          * 4\n"
         "          * 5\n"
         "   Which: stream wasn't finished"));
   });
 }