Rename the package to "test".

test/frontend/matcher/prints_test.dart

 // Copyright (c) 2014, 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", () {
     test("passes with an expected print", () {
       expect(() => print("Hello, world!"), prints("Hello, world!\n"));
     });
 
     test("combines multiple prints", () {
@@ skipping 122 matching lines @@
 
     test("won't let the test end until the Future completes", () {
       return expectTestBlocks(() {
         var completer = new Completer();
         expect(() => completer.future, prints(isEmpty));
         return completer;
       }, (completer) => completer.complete());
     });
   });
 }