Date String Parser
Should take a string representing a period of time and return a number of milliseconds representing the amount of time.
The string should be of the form
1y 2w 3d 4m
Where y is year, w is week, d is day and m is minute (if that isn't obvious)
Should
- accept the arguments in any order i.e.
1d 3wis valid - accept decimal points i.e.
1.3wweeks
Should not
- accept more than one of each denomination i.e. '1y 1y' is invalid
- accept minus numbers i.e.
Bonus Points
A function which takes the output of the original function and returns a string of the format shown above.