Upgrade pub to work with crypto 1.0.0 or later.

test/global/activate/activate_hosted_after_git_test.dart

Index: test/global/activate/activate_hosted_after_git_test.dart
diff --git a/test/global/activate/activate_hosted_after_git_test.dart b/test/global/activate/activate_hosted_after_git_test.dart
index 50e1c8d4b03233e30ecfca044146b037c17e229d..000f04118ae09fd33e1ed296cfc6385739dfd4fd 100644
--- a/test/global/activate/activate_hosted_after_git_test.dart
+++ b/test/global/activate/activate_hosted_after_git_test.dart
@@ -2,8 +2,6 @@
 // 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/io.dart';
-
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';