EmployeeTester

Adjusted the EmployeeTester with more accurate output
ProgrammerTester

-adjust setOvertimePay + addOvertimePay so it cannot go below zero but
allows for negitave adjustments
-adjust Employee setters to return booleans
- adjust getSalary and getPay for programmer and Employee
- adjust toString of Programmer
Clean up

Cleaned up code:
- getSalary now returns BigDecimal ** MAKE SURE TO ASK ABOUT **
Finish

Finished Assignment