Add minimal yaml support to the engine

pkg/analyzer/test/src/task/test_all.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.
 
 library analyzer.test.src.task.test_all;
 
 import 'package:unittest/unittest.dart';
 
 import '../../utils.dart';
 import 'dart_test.dart' as dart_test;
 import 'dart_work_manager_test.dart' as dart_work_manager_test;
 import 'driver_test.dart' as driver_test;
 import 'general_test.dart' as general_test;
 import 'html_test.dart' as html_test;
 import 'html_work_manager_test.dart' as html_work_manager_test;
 import 'incremental_element_builder_test.dart'
     as incremental_element_builder_test;
 import 'inputs_test.dart' as inputs_test;
 import 'manager_test.dart' as manager_test;
 import 'model_test.dart' as model_test;
 import 'options_test.dart' as options_test;
 import 'options_work_manager_test.dart' as options_work_manager_test;
 import 'strong_mode_test.dart' as strong_mode_test;
+import 'yaml_test.dart' as yaml_test;
 
 /// Utility for manually running all tests.
 main() {
   initializeTestEnvironment();
   group('task tests', () {
     dart_test.main();
     dart_work_manager_test.main();
     driver_test.main();
     general_test.main();
     html_test.main();
     html_work_manager_test.main();
     incremental_element_builder_test.main();
     inputs_test.main();
     manager_test.main();
     model_test.main();
     options_test.main();
     options_work_manager_test.main();
     strong_mode_test.main();
+    yaml_test.main();
   });
 }