random pick an incomplete task instead of go with sequential order

app.py

@@ -72,7 +72,7 @@ class AppSimulator:
                 system_data = json_repair.loads(row['value'])
 
         self.app_name = app_name
-        smallest_index = find_smallest_incomplete_task(app_name)
+        smallest_index = find_random_incomplete_task(app_name)
         if smallest_index is None:
             return "All tasks in this app have been completed!"
         self.smallest_index = smallest_index