Add missing newline after Actual value in fail message.

pkg/scheduled_test/lib/src/scheduled_future_matchers.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_future_matchers;
 
 import 'dart:async';
 
 import 'package:stack_trace/stack_trace.dart';
 
@@ skipping 22 matching lines @@
 ///
 /// [description] is an optional tag that can be used to identify the completion
 /// matcher in error messages.
 ///
 /// This differs from the `completion` matcher in `unittest` in that it pipes
 /// any errors in the Future to [currentSchedule], rather than reporting them in
 /// the [expect]'s error message.
 Matcher completion(matcher, [String description]) =>
     new _ScheduledCompletes(wrapMatcher(matcher), description);
 
-class _ScheduledCompletes extends BaseMatcher {
+class _ScheduledCompletes extends Matcher {
   final Matcher _matcher;
   final String _description;
 
   const _ScheduledCompletes(this._matcher, this._description);
 
   bool matches(item, Map matchState) {
     if (item is! Future) return false;
 
     // TODO(nweiz): parse the stack, figure out on what line these were called,
     // and include that in their descriptions
@@ skipping 23 matching lines @@
 
   Description describe(Description description) {
     if (_matcher == null) {
       description.add('completes successfully');
     } else {
       description.add('completes to a value that ').addDescriptionOf(_matcher);
     }
     return description;
   }
 }