Merge pull request #955 from MichaelRFairhurst/remove-unused-import

Remove unused dart:async import
diff --git a/test/utils.dart b/test/utils.dart
index 2d1ab06..b22f73f 100644
--- a/test/utils.dart
+++ b/test/utils.dart
@@ -4,7 +4,6 @@
 
 library dart_style.test.utils;
 
-import 'dart:async';
 import 'dart:io';
 import 'dart:mirrors';