also add a basic test

test/dune

@@ -0,0 +1,3 @@
+(test
+ (name t_fib)
+ (libraries moonpool))

test/t_fib.ml

@@ -0,0 +1,50 @@
+open Moonpool
+
+let pool = Pool.create ~min:4 ()
+
+let rec fib x =
+  if x <= 1 then
+    1
+  else
+    fib (x - 1) + fib (x - 2)
+
+let () = assert (List.init 10 fib = [ 1; 1; 2; 3; 5; 8; 13; 21; 34; 55 ])
+let fibs = Array.init 30 (fun n -> Fut.spawn ~on:pool (fun () -> fib n))
+let res = Fut.join_array fibs |> Fut.wait_block
+
+let () =
+  assert (
+    res
+    = Ok
+        [|
+          1;
+          1;
+          2;
+          3;
+          5;
+          8;
+          13;
+          21;
+          34;
+          55;
+          89;
+          144;
+          233;
+          377;
+          610;
+          987;
+          1597;
+          2584;
+          4181;
+          6765;
+          10946;
+          17711;
+          28657;
+          46368;
+          75025;
+          121393;
+          196418;
+          317811;
+          514229;
+          832040;
+        |])