update analyzer and code_transformers version and use mock sdk from code transformers

lib/build/html_import_annotation_recorder.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 web_components.build.html_import_recorder_inliner;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:barback/barback.dart';
 import 'package:initialize/transformer.dart';
@@ skipping 16 matching lines @@
 
   /// Applies to anything named `HtmlImport` which annotates a library.
   bool shouldApply(InitializerPluginData pluginData) {
     var annotationElement = pluginData.initializer.annotationNode.element;
     var logger = pluginData.logger;
     DartType type;
     if (annotationElement is ConstructorElement) {
       type = annotationElement.returnType;
     } else if (annotationElement is PropertyAccessorElement) {
       type = annotationElement.variable.propagatedType;
+      if (type == null) {
+        type = pluginData.resolver.evaluateConstant(annotationElement.library,
+            pluginData.initializer.annotationNode.name).value.type;
+      }
     } else {
       logger.error('Unsupported annotation type. Only constructors and '
           'properties are supported as initializers.');
       return false;
     }
     if (type.name != 'HtmlImport') return false;
     if (pluginData.initializer.targetElement is! LibraryElement) {
       logger.error('Invalid HtmlImport annotation on non-library element.');
       return false;
     }
@@ skipping 40 matching lines @@
       return null;
     }
 
     importPaths
         .add(normalizeHtmlImportPath(originalImportPath, package, libPath));
 
     // Don't emit an InitEntry.
     return null;
   }
 }