Added a very complicated AsyncIterableReader class.

The class was already implemented in
"https://deno.land/std@0.144.0/streams/conversion.ts".  So, I litterally
lost 1 day of work!  I hate myself.

tests/utils.ts

@@ -1,12 +1,17 @@
 
 
-export function* randomNumbers(seed: number, max: number) : Generator<number> {
+export function* randomNumbers(seed: number, max: number, maxResult: number|undefined = undefined) : Generator<number> {
     const a = 48271;
     const m =  2147483647;
     max = Math.floor(max);
+    let i = 0;
     while (true) {
         seed = (a * seed) % m; 
         yield seed % max;
+        i ++;
+        if(maxResult !== undefined && i >= maxResult){
+          return;
+        }
     }
 }