Refactored clock() and human_time() functions
Refactored clock() and human_time() functions

- Removed HAS_RUSAGE variable in favour of a try-except block that
utilizes the fact that the clock() now returns None as the second
return value if the resource module cannot be imported.
- Changed the first scale value to a float to match the others.

nightfury063/EulerPy,beni55/EulerPy,iKevinY/EulerPy,Enzime/EulerPy