Updating Angular version

third_party/pkg/angular/lib/tools/io_impl.dart

 library angular.io_impl;
 
 import 'dart:io';
-import 'io.dart';
+import 'package:angular/tools/io.dart';
 
 class IoServiceImpl implements IoService {
 
   String readAsStringSync(String filePath) =>
       new File(filePath).readAsStringSync();
 
   void visitFs(String rootDir, FsVisitor visitor) {
     Directory root = new Directory(rootDir);
     if (!FileSystemEntity.isDirectorySync(rootDir)) {
       throw 'Expected $rootDir to be a directory!';
     }
     root.listSync(recursive: true, followLinks: true).forEach((entity) {
       if (entity.statSync().type == FileSystemEntityType.FILE) {
         visitor(entity.path);
       }
     });
   }
 }