Rename the package to "test".

test/frontend/matcher/throws_test.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.
 
 import 'dart:async';
 
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 import '../../utils.dart';
 
 void main() {
   group("synchronous", () {
     group("[throws]", () {
       test("with a function that throws an error", () {
         expect(() => throw 'oh no', throws);
       });
 
@@ skipping 122 matching lines @@
       test("won't let the test end until the Future completes", () {
         return expectTestBlocks(() {
           var completer = new Completer();
           expect(completer.future, throwsA('oh no'));
           return completer;
         }, (completer) => completer.completeError('oh no'));
       });
     });
   });
 }