Java Classwork #8 (MeanMedianRange)
08) Write a Java program contained in a single file named "MeanMedianRange.java"
    (or "Main.java" if using Replit) that has the user enter an unlimited number of
    integers, one per line.  After the user presses the ENTER key on an empty line
    by itself, the program should compute and display the mean, median, and range of
    the entered numbers (please label the output).  Since the mean and median of a
    set of integers can be a double, use the 'printf' method to always display the
    mean and median (but not the range) rounded to exactly two decimal places.
    Also, be sure to gracefully handle the case where the user does not enter any
    numbers, as well as the case where the user enters only one number.

    For this program you should use the 'ArrayList' class to create an array of
    integers (the list must contain integers, not strings).  In addition to
    'main', you should have a separate method that gets the integers from the
    user, another method that computes and displays the mean, another method for
    computing and displaying the median, and another method to compute and display
    the range of the numbers.  You may use additional methods if you wish.

    In this program you are allowed to use only one ArrayList, and you may not use
    any other type of List or Collection anywhere in your program (although you
    may use the 'Collections' class to sort your ArrayList).  Other than the
    ArrayList of integers, you may not use any global variables for this
    assignment.  Also, you must use a 'try-catch' block to error trap for "bad"
    user input.  If the user enters a non-integer (a double or a string), discard
    the entry, display an appropriate message, and then continue to collect data.


ADVANCED OPTION FOR CLASSWORK #8
    Create an additional method in your program that computes and displays the
    mode(s) of the integers entered by the user.  Remember that a set of numbers
    can have multiple modes.  If you wish, you may use an additional ArrayList
    for this advanced option.