Install barback from a hosted source in all tests.

test/transformer/exclusion/exclude_asset_glob_test.dart

Index: test/transformer/exclusion/exclude_asset_glob_test.dart
diff --git a/test/transformer/exclusion/exclude_asset_glob_test.dart b/test/transformer/exclusion/exclude_asset_glob_test.dart
index 5518ac0d5724cd49605ac2274dbf849306e33dd5..904e608060bcefc9f304c31e23352d7eccdd7a76 100644
--- a/test/transformer/exclusion/exclude_asset_glob_test.dart
+++ b/test/transformer/exclusion/exclude_asset_glob_test.dart
@@ -10,6 +10,8 @@ import '../../serve/utils.dart';
 
 main() {
   integration("allows a glob to exclude", () {
+    serveBarback();
+
     d.dir(appPath, [
       d.pubspec({
         "name": "myapp",
@@ -19,7 +21,8 @@ main() {
               "\$exclude": "**/foo.txt"
             }
           }
-        ]
+        ],
+        "dependencies": {"barback": "any"}
       }),
       d.dir("lib", [d.dir("src", [
         d.file("transformer.dart", REWRITE_TRANSFORMER)
@@ -33,8 +36,7 @@ main() {
       ])
     ]).create();
 
-    createLockFile('myapp', pkg: ['barback']);
-
+    pubGet();
     pubServe();
     requestShould404("foo.out");
     requestShouldSucceed("bar.out", "bar.out");