Increase hashable upper bound

heist.cabal

@@ -193,7 +193,7 @@ Library
     directory-tree             >= 0.10    && < 0.13,
     dlist                      >= 0.5     && < 1.1,
     filepath                   >= 1.3     && < 2,
-    hashable                   >= 1.1     && < 1.5,
+    hashable                   >= 1.1     && < 2,
     lifted-base                >= 0.2     && < 0.3,
     map-syntax                 >= 0.3     && < 0.4,
     monad-control              >= 0.3     && < 1.1,