Fix DataFamilies export test.

Author: Philipp Schuster

tests/exports/DataFamilies.hs

@@ -1,12 +1,13 @@
 {-# LANGUAGE TypeFamilies #-}
 module DataFamilies (
+    Vector,
     ListLike(..),
     Vector(..)) where
 
 data family Vector a
 
 class ListLike a where
   type I a
-  h :: a -> I a
+  method1 :: a -> I a
 
 newtype instance Vector () = U_Vector ()