Bring test suite up to date

test/doctests.hs

@@ -1,11 +1,13 @@
+{-# LANGUAGE CPP #-}
 module Main where
 
 import Test.DocTest
 
 main :: IO ()
-main = doctest [
-    "-package"
-  , "ghc"
+main = doctest
+  [ "-package", "ghc"
+  , "-package", "transformers-" ++ VERSION_transformers
+  , "-package", "directory-" ++ VERSION_directory
   , "-XConstraintKinds", "-XFlexibleContexts", "-XScopedTypeVariables", "-XRecordWildCards", "-XNamedFieldPuns"
   , "-idist/build/autogen/"
   , "-optP-include"