add custom_element package

pkg/mdv/test/analyzer_test.dart

Index: pkg/mdv/test/analyzer_test.dart
diff --git a/samples/tests/samples/standalone/time_test.dart b/pkg/mdv/test/analyzer_test.dart
similarity index 61%
copy from samples/tests/samples/standalone/time_test.dart
copy to pkg/mdv/test/analyzer_test.dart
index 32a8726ccaba707e59d14c9eb5589b446682c6d3..d92a95ff476efad6e58fee5cd0a67f7400561793 100644
--- a/samples/tests/samples/standalone/time_test.dart
+++ b/pkg/mdv/test/analyzer_test.dart
@@ -2,13 +2,11 @@
 // 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 '../../../time/time_server.dart' as time;
+library mdv.test.analyzer_test;
 
-// @static-clean
+import 'package:mdv/mdv.dart';
 
-/**
- * This test exists to ensure that the time sample compiles without errors.
- */
-void main() {
+// @static-clean
 
-}
+// This test ensures CustomElement compiles without errors.
+void main() {}