pkg/isolate: support travis and coveralls

test/test_all.dart

+// Copyright (c) 2015, 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 isolate.test.test_all;
+
+import 'package:unittest/unittest.dart';
+
+import 'isolaterunner_test.dart' as isolaterunner;
+import 'ports_test.dart' as ports;
+import 'registry_test.dart' as registy;
+
+void main() {
+  group('IsolateRunner', isolaterunner.main);
+  group('ports', ports.main);
+  group('registry', registy.main);
+}