Add a method to the ArraySum class named
signed_array_sum.  The first parameter is a boolean, the second
parameter is an array of integers.  When the first parameter is true,
the function returns the sum of all the elements in the array that are
positive (greater than zero).  When the first parameter is false, the
function returns the sum of all the negative elements.  In the
ArraySumDemo class, add three more well-chosen arrays of test data.
In the main method of the ArraySumDemo class, add statements to test
signed_array_sum with both values of the first parameter on six_ones,
bentley, and your three new arrays.

Due Tuesday Oct 2