Does not work with nim 1.0.0+

[kaushalmodi]

Hello,

There was a backward incompatible change in nim 1.0.0 that removed isDigit for string args.

So with newer nim versions, this fails:

git clone https://github.com/johnscillieri/psutil-nim psutil
cd psutil
nim c -r tests/test_posix.nim    

psutil/src/psutil/psutil_linux.nim(158, 47) Error: type mismatch: got <string>
but expected one of:
proc isDigit(c: char): bool
  first type mismatch at position: 1
  required type for c: char
  but expression 'it.path' is of type: string

expression: isdigit(it.path)

[kaushalmodi]

Closing this as this is already fixed in the maintained fork https://github.com/juancarlospaco/psutil-nim .