added pastMeetings and futureMeetings to serialization
written barebones test - passes so far
made unique id set size + 1 so 0 is not an id
tested addNewContact - works
added NullPException if set is empty, as in testing 0 was returned as a bad id (as that is what offendingId is initialized to)
tested what happened with empty set - 0 was given as a bad id so I amended emthod in contactmanager to throw a NullPointer
test passes with proper inputs will now try some bad ids
test still passes - must be problem with boolean isBadId