nits

Author: kevmoo

bin/dartdoc.dart

@@ -47,10 +47,9 @@ main(List<String> arguments) async {
   }
 
   final bool sdkDocs = args['sdk-docs'];
+  final bool showProgress = args['show-progress'];
 
-  final showProgress = args['show-progress'] as bool;
-
-  var readme = args['sdk-readme'] as String;
+  final String readme = args['sdk-readme'];
   if (readme != null && !(new File(readme).existsSync())) {
     stderr.writeln(
         " fatal error: unable to locate the SDK description file at $readme.");