Merge pull request dart-lang/test_process#20 from dart-lang/srawlins-patch-1

Remove unused dart:async imports
diff --git a/pkgs/test_process/lib/test_process.dart b/pkgs/test_process/lib/test_process.dart
index d9dff5d..301ce9d 100644
--- a/pkgs/test_process/lib/test_process.dart
+++ b/pkgs/test_process/lib/test_process.dart
@@ -2,7 +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:async';
 import 'dart:convert';
 import 'dart:io';