Removed the unused Trat type for clocks

src/types.ml

@@ -119,9 +119,7 @@ module type S = sig
 end
 
 module Basic : BASIC_TYPES = struct
-  type t = Tstring | Tint | Treal | Tbool | Trat
-  (* Actually unused for now. Only place where it can appear is in a clock
-     declaration *)
+  type t = Tstring | Tint | Treal | Tbool 
 
   let type_string_builder = Tstring
   let type_int_builder = Tint
@@ -140,8 +138,6 @@ module Basic : BASIC_TYPES = struct
       fprintf fmt "string"
     | Tbool ->
       fprintf fmt "bool"
-    | Trat ->
-      fprintf fmt "rat"
 
   let pp_c = pp