sleep-sort works by creating a task for every number to be sorted. The task
will "sleep" n number of milliseconds and then push the number onto an array.
When all tasks are done, the array is returned sorted.
$ npm install sleep-sort
$ sleep-sort 2 7 89 94 77 4 6 9 6 3
3 2 4 6 6 9 7 77 89 94