This module is a python script that will take 2 command line arguments,
(a string and a number) and read input formatted like ['files/grade.csv']
from standard input.

If the string on the command line is found anywhere on a line of input, 
then the grade on that line should be changed to that number and the 
modified line printed to the standard out. Lines that do not match the string
should be printed back to standard out unchanged.