Create Fraction.java

/** Class used to represent a ration of two integers. Includes a mutator method
 *  that allows user to set the numerator and denominator. Includes a method
 *  that returns the value of numerator divided by denominator. Includes a 
 *  method that outputs the value of the fraction in its lowest terms (most
 *  simplified) See "MakeFractions.java" for main method.  
 */