switch tests from 'unittest' to 'test' library
diff --git a/test/coded_buffer_reader_test.dart b/test/coded_buffer_reader_test.dart
index 7a50002..bd9120b 100755
--- a/test/coded_buffer_reader_test.dart
+++ b/test/coded_buffer_reader_test.dart
@@ -8,7 +8,7 @@
 import 'dart:typed_data';
 
 import 'package:protobuf/protobuf.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 import 'test_util.dart';