Created JUnit test case for Category class
Added setUp() method to Category test case
Cut and paste existing test methods from CommitmentTest into CategoryTest
Merge branch 'feature/Tests' of https://github.com/CS3733Team1/wpi-suite into feature/Tests
Merge branch 'dev' of https://github.com/CS3733Team1/wpi-suite into feature/Tests
Merge branch 'feature/Tests' into dev
Merge branch 'dev' of https://github.com/CS3733Team1/wpi-suite into dev