Add missing export

Author: garyb

README.md

@@ -36,6 +36,8 @@
 
     chown :: forall eff. FilePath -> Number -> Number -> Callback eff Unit -> Eff (fs :: FS | eff) Unit
 
+    exists :: forall eff. FilePath -> (Boolean -> Eff eff Unit) -> Eff (fs :: FS | eff) Unit
+
     link :: forall eff. FilePath -> FilePath -> Callback eff Unit -> Eff (fs :: FS | eff) Unit
 
     mkdir :: forall eff. FilePath -> Callback eff Unit -> Eff (fs :: FS | eff) Unit

src/Node/FS/Async.purs

@@ -22,6 +22,7 @@ module Node.FS.Async
   , writeTextFile
   , appendFile
   , appendTextFile
+  , exists
   ) where
 
 import Control.Monad.Eff