Allow doclayout 0.5. (#3)

Note:  we don't include bindings to the new functions from doclayout
0.5.  Maybe it's not necessary, but if we did we'd need a lower bound
too.

Author: jgm

hslua-module-doclayout.cabal

@@ -31,7 +31,7 @@ source-repository head
 
 common common-options
   build-depends:       base              >= 4.11   && < 5
-                     , doclayout         >= 0.2    && < 0.5
+                     , doclayout         >= 0.2    && < 0.6
                      , hslua             >= 2.3    && < 2.4
                      , text              >= 1.2    && < 2.2