Drop support for older Barback versions.

test/transformer/loads_a_transformer_defined_in_an_exported_library_test.dart

Index: test/transformer/loads_a_transformer_defined_in_an_exported_library_test.dart
diff --git a/test/transformer/loads_a_transformer_defined_in_an_exported_library_test.dart b/test/transformer/loads_a_transformer_defined_in_an_exported_library_test.dart
index d0c5263f8404f31e877ffeb1c972046ef5492bac..d1d9bd81080656ac40f35d001a73a4419ba0314b 100644
--- a/test/transformer/loads_a_transformer_defined_in_an_exported_library_test.dart
+++ b/test/transformer/loads_a_transformer_defined_in_an_exported_library_test.dart
@@ -9,29 +9,27 @@ import '../test_pub.dart';
 import '../serve/utils.dart';
 
 main() {
-  withBarbackVersions("any", () {
-    integration("loads a transformer defined in an exported library", () {
-      d.dir(appPath, [
-        d.pubspec({
-          "name": "myapp",
-          "transformers": ["myapp"]
-        }),
-        d.dir("lib", [
-          d.file("myapp.dart", "export 'src/transformer.dart';"),
-          d.dir("src", [
-            d.file("transformer.dart", REWRITE_TRANSFORMER)
-          ])
-        ]),
-        d.dir("web", [
-          d.file("foo.txt", "foo")
+  integration("loads a transformer defined in an exported library", () {
+    d.dir(appPath, [
+      d.pubspec({
+        "name": "myapp",
+        "transformers": ["myapp"]
+      }),
+      d.dir("lib", [
+        d.file("myapp.dart", "export 'src/transformer.dart';"),
+        d.dir("src", [
+          d.file("transformer.dart", REWRITE_TRANSFORMER)
         ])
-      ]).create();
+      ]),
+      d.dir("web", [
+        d.file("foo.txt", "foo")
+      ])
+    ]).create();
 
-      createLockFile('myapp', pkg: ['barback']);
+    createLockFile('myapp', pkg: ['barback']);
 
-      pubServe();
-      requestShouldSucceed("foo.out", "foo.out");
-      endPubServe();
-    });
+    pubServe();
+    requestShouldSucceed("foo.out", "foo.out");
+    endPubServe();
   });
 }