VOL-1255: Fixed an issue with the proxy implementation

- Had to change the model slightly to mimic a polymorphic behaviour

Change-Id: I12017cdfedf5c0ed05243245aa2a811556222e0f
diff --git a/db/model/branch_test.go b/db/model/branch_test.go
index 456ec79..1f2eec2 100644
--- a/db/model/branch_test.go
+++ b/db/model/branch_test.go
@@ -27,7 +27,7 @@
 )
 
 func Test_ConfigBranch_New(t *testing.T) {
-	node := &Node{}
+	node := &node{}
 	hash := fmt.Sprintf("%x", md5.Sum([]byte("origin_hash")))
 	origin := &NonPersistedRevision{
 		Config:   &DataRevision{},