How to add test (success) cases:
- Add DECAF (.dcf) file.
- Add compare (.cmp) file that gives expected output.
- Run testall.sh (make before using testall)

How to add test (fail) cases:
- Add DECAF (.dcf) file.
- Add compare (.cmp) file that gives expected error.
- Run testall.sh (make before using testall)

How to read output:
- All output put in tests/ folder
- Executable produced (if success case)
- Output file (.out) is output of binary executable (or error message for fail
  cases)
- Diff (.diff) file is diff between expected (.cmp) and actual (.out).
