add tools module tests

src/ftest.ml

@@ -1,4 +1,6 @@
 open Gfile
+open Tools
+open Ffalgo
 
 let () =
 
@@ -22,7 +24,9 @@ let () =
 
   (* Open file *)
   let graph = from_file infile in
-
+  (* let graph2 = clone_nodes graph in *)
+  (* let graph2 = gmap (gmap (gmap graph int_of_string) (fun x -> x + 1)) string_of_int in *)
+  (* let graph2 = gmap (add_arc (gmap graph int_of_string) 2 1 13) string_of_int in *)
   (* Rewrite the graph that has been read. *)
   let () = export outfile graph in