Fix repeat function to throw an error for negative counts instead of returning a message

Author: Payman IB

Sprint-3/2-practice-tdd/repeat.js

@@ -1,6 +1,6 @@
 function repeat(str , count) {
   if (count < 0) {
-    return "Count must be a non-negative integer";
+    throw new Error("Count must be a non-negative integer");
   }
   if (count === 0) {
     return "";
@@ -12,5 +12,4 @@ function repeat(str , count) {
   console.log(repeat("hello", -2));
 
 
-
 module.exports = repeat;