Is it possible to up/downvote through your site?

Building a Haskell course based on the “Purely functional data structures” book (http://www.amazon.com/Purely-Functional-Structures-Chris-Okasaki/dp/0521663504). I’m translating the book’s code to Haskell and adding quickcheck based doctests. I have a separate templates/ directory where you only have the tests and only the function’s signature with an empty body, that’s where you’re supposed to work on filling the function definitions and getting the tests to pass. The project is at https://github.com/djv/pfds