pkg/unittest: Removed references to expectAsync[Until]X in docs

pkg/unittest/lib/vm_config.dart

Index: pkg/unittest/lib/vm_config.dart
diff --git a/pkg/unittest/lib/vm_config.dart b/pkg/unittest/lib/vm_config.dart
index 685518eeaedad1184e8b1f32e4213f2cba127952..77e91e35c43c8c277d5dee24f1b729aad187c0d6 100644
--- a/pkg/unittest/lib/vm_config.dart
+++ b/pkg/unittest/lib/vm_config.dart
@@ -2,9 +2,7 @@
 // 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.
 
-/**
- * A simple unit test library for running tests on the VM.
- */
+/// A simple unit test library for running tests on the VM.
 library unittest.vm_config;
 
 import 'dart:async';