Move minitest.dart into the expect package.

pkg/dev_compiler/test/codegen/lib/html/js_function_getter_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.
 
 @JS()
 library js_function_getter_test;
 
 import 'dart:html';
 
 import 'package:js/js.dart';
-import 'package:minitest/minitest.dart';
+import 'package:expect/minitest.dart';
 
 _injectJs() {
   document.body.append(new ScriptElement()
     ..type = 'text/javascript'
     ..innerHtml = r"""
   var bar = { };
 
   bar.instanceMember = function() {
     if (this !== bar) {
       throw 'Unexpected this!';
@@ skipping 74 matching lines @@
       expect(dynamicStatic(0), equals(1));
       expect(dynamicStatic(0,0), equals(2));
       expect(dynamicStatic(0,0,0,0,0,0), equals(6));
     });
 
     test('typedef function', () {
       expect(foo.bar.add(4,5), equals(9));
     });
   });
 }