CS 132 Assignment 1, due Friday, February 8

A fraction a/b can be represented by the two integers, a numerator and denominator 
as (a,b) where a is the numerator and b is the denominator. Operations can then be 
expressed in terms of the pairs, e.g.

   (a,b) + (c,d) = (ad + bc, bd)
   (a,b) - (c,d) = (ad - bc, bd)
   (a,b) * (c,d) = (ac, bd)
   (a,b) / (c,d) = (ad, bc)


Build a fraction class that represents the numerator and denominator as integers and 
provides at least the following operations:

    Constructor(s)
    Output (writing the fraction)
    Functions for returning the numerator and denominator
    Arithmetic operations that add, subtract, multiply and divide two fractions
    (build in some form of error checking for division by zero). 
    A function to determine if a number is equal to 0  

You will need to build a driver to test your class.

*Add another function that reduces a fraction to lowest terms.