Use "package:" imports for pub.

test/implicit_barback_dependency_test.dart

Index: test/implicit_barback_dependency_test.dart
diff --git a/test/implicit_barback_dependency_test.dart b/test/implicit_barback_dependency_test.dart
index 0d16e51cd8c3ee09f179c89c5d87755409d793f8..88d8a4fd71ca46f1c2073e8b3151bd5bd5d1b182 100644
--- a/test/implicit_barback_dependency_test.dart
+++ b/test/implicit_barback_dependency_test.dart
@@ -2,11 +2,11 @@
 // 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.
 
+import 'package:pub/src/barback.dart' as barback;
 import 'package:pub_semver/pub_semver.dart';
 
 import 'descriptor.dart' as d;
 import 'test_pub.dart';
-import '../lib/src/barback.dart' as barback;
 
 main() {
   initConfig();