Move minitest.dart into the expect package.

pkg/dev_compiler/test/codegen/lib/html/element_types_constructors2_test.dart

 // Copyright (c) 2012, 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:html';
 
-import 'package:minitest/minitest.dart';
+import 'package:expect/minitest.dart';
 
 main() {
   check(String name, bool fn(), [bool supported = true]) {
     test(name, () {
       var expectation = supported ? returnsNormally : throws;
       expect(() {
         expect(fn(), isTrue);
       }, expectation);
     });
   }
@@ skipping 10 matching lines @@
     check('h4', () => new HeadingElement.h4() is HeadingElement);
     check('h5', () => new HeadingElement.h5() is HeadingElement);
     check('h6', () => new HeadingElement.h6() is HeadingElement);
     check('iframe', () => new IFrameElement() is IFrameElement);
     check('img', () => new ImageElement() is ImageElement);
     check('input', () => new InputElement() is InputElement);
     check('keygen',
         () => new KeygenElement() is KeygenElement, KeygenElement.supported);
   });
 }