next_bigger
[ASSIGNMENT]:

  Next bigger number with 
  the same digits
 TASK:
You have to create a function that takes 
a positive integer number and returns the 
next bigger number formed by the same 
digits:

  next_bigger(12) --> return 21 
 next_bigger(513) --> return 531 
 next_bigger(2017) --> return 2071 

If no bigger number can be composed using 
those digits, return -1:

  next_bigger(9) --> return -1 
 next_bigger(111) --> return -1 
 next_bigger(531) --> return -1 


    HappyCodings!:) by @boolean maybe
Next bigger number with the same digits
