Write a function that converts an integer n into a string representing
n in base b.  You should assume that b is at most 10 and use the standard
digits to represent numbers from 0 to b-1.

For example: 
for n=73 and b=10 the string would be "73".
for n=128 and b=2 the string would be "10000000". 
for n=11 and b=9 the string would be "12".

Use your function to write a program that computes and prints the
representation for:

n=255 and b=2
n=33 and b=8
n=71 and b=5
n=40 and b=2