Write a function, which takes a non-negative integer (seconds) as input and returns the time in a human-readable format (HH:MM:SS) HH = hours, padded to 2 digits, range: 00 - 99 MM = minutes, padded to 2 digits, range: 00 - 59 SS = seconds, padded to 2 digits, range: 00 - 59 The maximum time never exceeds 359999 (99:59:59) You can find some examples in the test fixtures. Solution function addZer..
