chore(docker/haskell): One more dependency

Author: goblivend

haskell/Main.cabal

@@ -17,7 +17,8 @@ executable Main
                       parallel >=3.2.2.0,
                       Unique >=0.4.7.9,
                       extra >=1.8,
-                      regex-tdfa ^>= 1.3.2
+                      regex-tdfa ^>= 1.3.2,
+                      split >=0.2.5
 
     -- Directories containing source files.
     hs-source-dirs:   .