Renamed the file from dataManipulation to DataManipulation
Added an assert statement to make sure that ezC.totalTaskList is never null
Added a markAsCompleted method to mark a task as completed
Removed the unit test for TaskFileReader
Edited Yui Wei's ExactMatchSearcher call to match the format.
Added an isExactMatch() method to return a boolean answer of whether such a task already exists in the file and is an exact match.