Updated add(Task task) method to utilise bundle object
Updated add(Task task) method to utilise Bundle Object

Why is this change necessary?
- All failure messages are handled by Bundle object. This standardizes the
  way failure messages are handled across the program.

How did it address the issue?
- Instead of returning a boolean variable to Database, returning a Bundle
  object allows for the failure message to be passed back to the Database.
Added new methods to Task object

New methods added:
displayStartDate()
displayStartTime()
displayEndDate()
displayEndTime()
displayDate()
displayTime()

Why is this change necessary?
- These extra methods return only the date and only the time. It is
  necessary to parse the date and the time separately in
  GoogleCalendarManager, because of the way google APIs work.

How does it address the issue?
- By adding these new methods, GoogleCalendarManager is able to call the
  task object, and directly obtain the values, without the need to edit
  the string within GoogleCalendarManager itself.
Added new JUnit test cases

New test cases added:

testGetStartDate()
testGetStartTime()
testGetEndDate()
testGetEndTime()
Made Task object work in GoogleCalendarManager

Changed from stubs to functional methods.
The methods:
- getSummary
- getStartDate()
- getEndDate()
- getStartTime()
- getEndTime()
GoogleCalendarManager functional, ready to receive calls from Database

- Removed all excess code from the test program that GoogleCalendarManager
  was built on
- Currently, the main method exists solely for testing purposes
- Print statements from every method exists solely for testing purposes
Edited Bundle keys for success

Why is this change necessary?
- To ensure different Bundle keys for successful add and successful delete
  to and from Google Calendar