Move minitest.dart into the expect package.

pkg/dev_compiler/test/codegen/lib/html/js_typed_interop_anonymous2_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_typed_interop_anonymous2_test;
 
 import 'dart:html';
 import 'dart:js' as js;
 
 import 'package:js/js.dart';
-import 'package:minitest/minitest.dart';
+import 'package:expect/minitest.dart';
 
 @JS() @anonymous
 class A {
   external factory A({B b});
 
   external B get b;
 }
 
 @JS() @anonymous
 class B {
@@ skipping 14 matching lines @@
 }
 
 main() {
   test('simple', () {
     var b = new B();
     var a = new A(b: b);
     expect(a.b, equals(b));
     expect(b.c, isNull);
   });
 }