Drop support for older Barback versions.

test/transformer/a_transformer_rejects_its_config_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.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 'package:scheduled_test/scheduled_test.dart';
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import '../serve/utils.dart';
 
 const REJECT_CONFIG_TRANSFORMER = """
 import 'dart:async';
 
 import 'package:barback/barback.dart';
 
 class RejectConfigTransformer extends Transformer {
   RejectConfigTransformer.asPlugin(BarbackSettings settings) {
     throw "I hate these settings!";
   }
 
   Future<bool> isPrimary(_) => new Future.value(true);
   Future apply(Transform transform) {}
 }
 """;
 
 main() {
-  withBarbackVersions("any", () {
-     integration("a transformer can reject is configuration", () {
-       d.dir(appPath, [
-         d.pubspec({
-           "name": "myapp",
-           "transformers": [{"myapp/src/transformer": {'foo': 'bar'}}]
-         }),
-         d.dir("lib", [d.dir("src", [
-           d.file("transformer.dart", REJECT_CONFIG_TRANSFORMER)
-         ])])
-       ]).create();
+   integration("a transformer can reject is configuration", () {
+     d.dir(appPath, [
+       d.pubspec({
+         "name": "myapp",
+         "transformers": [{"myapp/src/transformer": {'foo': 'bar'}}]
+       }),
+       d.dir("lib", [d.dir("src", [
+         d.file("transformer.dart", REJECT_CONFIG_TRANSFORMER)
+       ])])
+     ]).create();
 
-       createLockFile('myapp', pkg: ['barback']);
+     createLockFile('myapp', pkg: ['barback']);
 
-       var pub = startPubServe();
-       pub.stderr.expect(endsWith('Error loading transformer: I hate these '
-           'settings!'));
-       pub.shouldExit(1);
-     });
-  });
+     var pub = startPubServe();
+     pub.stderr.expect(endsWith('Error loading transformer: I hate these '
+         'settings!'));
+     pub.shouldExit(1);
+   });
 }