Fix analyzer hints and warnings in test/.

test/global/activate/outdated_binstub_test.dart

Index: test/global/activate/outdated_binstub_test.dart
diff --git a/test/global/activate/outdated_binstub_test.dart b/test/global/activate/outdated_binstub_test.dart
index ea891fb97ee419b012a0b11ad62267f489aa03b7..f84d555841911d02fb122fa710013582a3a291fe 100644
--- a/test/global/activate/outdated_binstub_test.dart
+++ b/test/global/activate/outdated_binstub_test.dart
@@ -2,12 +2,6 @@
 // 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.
 
-import 'dart:io';
-import 'dart:async';
-
-import 'package:path/path.dart' as p;
-import 'package:scheduled_test/scheduled_process.dart';
-import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../descriptor.dart' as d;