Updated to the latest versions of heist,snap and web routes boomerang.

Heya,

I made these changes on my own fork to get something working on the latest versions of all the dependencies. I thought that I'd swing them your way since you're a top hit on google for "snap web routes boomerang" :).

This builds so long as you do this workaround for transformers-compat (http://www.reddit.com/r/haskell/comments/26045a/if_youre_finding_cabal_cant_build_your_project/) but I'm happy if you want to tweak this around to how you had things before. I was trying to keep them as simple as possible but I got a bit diverted by all the updates to the new APIs.

Cheers,
Ben