To use the interpreter run "make" to compile everything
Run "interpreter < inputFile" where inputFile is some Racket
source code of your choosing and the results will print
to the terminal window.

All test files are in the ./test_files/ folder.
Files 1-4 are for the if/let assignment.
Files 5 and 6 are for the quote assignment.
Files 7-10 are for the define/lambda assignment.
Files 11-14 are for the primitives assignment.
Files 15-18 are for the final assignment.
Files 19 and onward are for testing anything else I may implement.

I have implemented these things beyond the assignment description:
    - null?
    - zero?
    - equal?
    - list?
    - length