Install barback from a hosted source in all tests.

test/transformer/runs_a_local_transform_on_the_application_package_test.dart

Index: test/transformer/runs_a_local_transform_on_the_application_package_test.dart
diff --git a/test/transformer/runs_a_local_transform_on_the_application_package_test.dart b/test/transformer/runs_a_local_transform_on_the_application_package_test.dart
index 7a13867429dc2dd8063b84dc5cb30544842e5559..9839bb36efec2534abc07eb15a263301b0b5b27c 100644
--- a/test/transformer/runs_a_local_transform_on_the_application_package_test.dart
+++ b/test/transformer/runs_a_local_transform_on_the_application_package_test.dart
@@ -10,10 +10,13 @@ import '../serve/utils.dart';
 
 main() {
   integration("runs a local transform on the application package", () {
+    serveBarback();
+
     d.dir(appPath, [
       d.pubspec({
         "name": "myapp",
-        "transformers": ["myapp/src/transformer"]
+        "transformers": ["myapp/src/transformer"],
+        "dependencies": {"barback": "any"}
       }),
       d.dir("lib", [d.dir("src", [
         d.file("transformer.dart", REWRITE_TRANSFORMER)
@@ -23,8 +26,7 @@ main() {
       ])
     ]).create();
 
-    createLockFile('myapp', pkg: ['barback']);
-
+    pubGet();
     pubServe();
     requestShouldSucceed("foo.out", "foo.out");
     endPubServe();