HashTable Completion of Testing

Tested:
Add (Adding two items with the same key value, adding three items with
the same key value, a new item with a different key value, adding the
exact same item)

Remove (removing an item with a non NULL overflow list, removing an item
that doesn't exist in the hash table, removing an item from an index's
overflow list)

displayItems (finding items in the index and display it, finding items
in the index's overflow lists and display it,)

Display (displays the entire hashtable including all the indexes and
their overflow lists)

displayKeySeq (sorts and displays the hashtable in ascending order)

PrintEff (calculates and prints out the values of a successful and an
failed search of the hashtable)

If anyone spots any errors, please let me know.