Basic Racket to JavaScript compiler.
Usage:
- To run tests: `racket test/test.rkt`
- If you have Racket code in a file called `sample.rkt` and want
to compile to JS, run `make sample.js` (and then to run: `node sample.js`)
Notes about behavior:
- type-checking is run time. If you type (add1 #f), it will compile, but throw an error when running