Updated the addFutureMeeting date check as it wasn't working
Added a check to ensure the IllegalArgumentException was working correctly
when a date in the past is specified
Added the code for addNewPastMeeting including the checks for the
parameters
Added the test for AddNewPastMeeting, one test checks all the exceptions
fire correctly and the other tests the functionality works with a valid
PastMeeting
Updaated the contructor to accept a notes parameter and assign it to the
local variable