Add flag to disable capturing stack traces.

utils/tests/pub/update/hosted/remove_removed_transitive_dependency_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 library pub_tests;
 
 import 'dart:io';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 
 main() {
+  initConfig();
   integration("removes a transitive dependency that's no longer depended "
       "on", () {
     servePackages([
       packageMap("foo", "1.0.0", [dependencyMap("shared-dep")]),
       packageMap("bar", "1.0.0", [
         dependencyMap("shared-dep"),
         dependencyMap("bar-dep")
       ]),
       packageMap("shared-dep", "1.0.0"),
       packageMap("bar-dep", "1.0.0")
@@ skipping 17 matching lines @@
         output: new RegExp(r"Dependencies updated!$"));
 
     d.packagesDir({
       "foo": "1.0.0",
       "bar": null,
       "shared-dep": "1.0.0",
       "bar-dep": null,
     }).validate();
   });
 }