Remove data/make-reference-files.hs.

I don't think this has been used for a long time.

data/make-reference-files.hs

@@ -1,27 +0,0 @@
-import System.Environment
-import System.Directory
-import Codec.Archive.Zip
-import qualified Data.ByteString.Lazy as BS
-import qualified Control.Exception as E
-import System.IO.Error (isDoesNotExistError)
-import System.FilePath
-
-mkzip :: String -> IO ()
-mkzip fmt = do
-  let dir    = "data" </> fmt
-      output = "data" </> "reference" <.> fmt
-  cd <- getCurrentDirectory
-  setCurrentDirectory dir
-  archive <- addFilesToArchive [OptRecursive] emptyArchive ["."]
-  setCurrentDirectory cd
-  removeIfExists output
-  BS.writeFile output $ fromArchive archive
-
-removeIfExists :: FilePath -> IO ()
-removeIfExists fileName = removeFile fileName `E.catch` handleExists
-  where handleExists e
-          | isDoesNotExistError e = return ()
-          | otherwise = E.throwIO e
-
-main :: IO ()
-main = getArgs >>= mkzip . (!!0)