Constructors
You will now create your class constructors--you should write two.
One constructor needs to
intialize the fracton to 1/1. The other needs to allow the class fractions
to be intialized by using a command like this in main: Fraction frac(1, 2).
It will also check to see if the user entered a denominator of 0,
and print out an error message and exit if that is the case.