Debug: added console logger

lib/debug.ml

@@ -5,7 +5,8 @@ open Bistro_engine
 let with_workflow w ~f =
   let open Scheduler in
   let db = Db.init_exn "_bistro" in
-  let sched = create ~np:8 ~mem:(`GB 8) db in
+  let loggers = [ Bistro_utils.Console_logger.create () ] in
+  let sched = create ~np:8 ~mem:(`GB 8) ~loggers db in
   let thread = eval_exn sched w in
   start sched ;
   Lwt_main.run thread