test rename overhaul: step 6 - isolate tests

tests/isolate/spawn_test.dart

 // Copyright (c) 2011, 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("SpawnTest");
 #import("dart:isolate");
-#import('../../../lib/unittest/unittest.dart');
+#import('../../lib/unittest/unittest.dart');
 
 main() {
   test("spawn a new isolate", () {
     SpawnedIsolate isolate = new SpawnedIsolate();
     isolate.spawn().then(expectAsync1((SendPort port) {
       port.call(42).then(expectAsync1((message) {
         Expect.equals(42, message);
       }));
     }));
   });
 }
 
 class SpawnedIsolate extends Isolate {
 
   SpawnedIsolate() : super() { }
 
   void main() {
     this.port.receive((message, SendPort replyTo) {
       Expect.equals(42, message);
       replyTo.send(42, null);
       this.port.close();
     });
   }
 
 }