Revert "Add mark done/undone to user stories"
Revert "Add mark done/undone to user stories"

This reverts commit ea4ae154a7bd039c07cb842bb18055fbfd449dac.

CS2103AUG2016-F10-C1/main,CS2103AUG2016-F10-C1/main,CS2103AUG2016-F10-C1/main