Add category color to event agenda and commitment all, added repeating events to event agenda
Merge branch 'dev' of https://github.com/magwitch324/wpi-suite into dev

# By TeresaZhao (3) and Andrew Roskuski (2)
# Via Andrew Roskuski
* 'dev' of https://github.com/magwitch324/wpi-suite:
  made getCategory return null for nonexistent category
  refactoring
  refactoring.
  finish up testing
  getCategory now returns null if you give it 0
Merge branch 'dev' of https://github.com/magwitch324/wpi-suite into dev
Removed unnecessary constructor
# By TeresaZhao (2) and Andrew Roskuski (1)
# Via TeresaZhao
* 'dev' of https://github.com/magwitch324/wpi-suite:
  common out unused method
  Moved adding of delete button to edit constrcutor, and fixed the behaviour of the save button on the commitment tab........... again
  added copyright