Change test data to illustrate that they /all/ must match

lib/koans/09_enums.ex

@@ -12,7 +12,7 @@ defmodule Enums do
   def less_than_five?(n), do: n < 5
   koan "Elements can have a lot in common" do
     assert Enum.all?([1 ,2 ,3], &less_than_five?/1) == ___
-    assert Enum.all?([6 ,7 ,8 ,9], &less_than_five?/1) == ___
+    assert Enum.all?([4, 6 ,8], &less_than_five?/1) == ___
   end
 
   def even?(n), do: rem(n, 2) == 0