Given two times in hours, minutes, and seconds (ie '15:04:24'), add or subtract them. This is a 24-hour clock. Output should be two digits for all numbers: hours, minutes, seconds (ie '04:02:09').
timeMath('01:24:31', '+', '02:16:05') === '03:40:36'
timeMath('01:24:31', '-', '02:31:41') === '22:52:50'