Bump hedgehog upper bound from <1.5 to <1.6

Author: thomasjm

system-linux-proc.cabal

@@ -50,6 +50,6 @@ test-suite test
 
   build-depends:       base                          >= 4.8         && < 5.0
                      , directory                     == 1.3.*
-                     , hedgehog                      >= 1.0         && < 1.5
+                     , hedgehog                      >= 1.0         && < 1.6
                      , pretty-show                   == 1.10.*
                      , system-linux-proc