Move minitest.dart into the expect package.

pkg/dev_compiler/test/codegen/lib/html/element_classes_svg_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:collection';
 import 'dart:html';
 import 'dart:svg' as svg;
 
-import 'package:minitest/minitest.dart';
+import 'package:expect/minitest.dart';
 
 // Test for `querySelectorAll(xxx).classes.op()` where the query returns mixed
 // Html and Svg elements.
 
 Element makeElementsContainer() {
   var e = new Element.html(
       '<ul class="yes foo">'
       '<li class="yes quux qux">'
       '</ul>');
   final svgContent = r"""
@@ skipping 167 matching lines @@
     expect(view(elements),
         '[[], [quux, qux], [qux], []]');
   });
 
   test('listContainsAll', () {
     var elements = elementsSetup();
     expect(elements.classes.containsAll(['qux', 'mornin']), isFalse);
     expect(elements.classes.containsAll(['qux', 'classy']), isTrue);
   });
 }