Update lein-ring to 0.8.11

Hi @weavejester,

Please could you merge this change to use lein-ring 0.8.11 and then cut a new release of compojure-template? (Note: I guess the new version of compojure-template would be 0.3.5 because 0.3.4 already exists on Clojars, although I'm not sure exactly where the source of that is ...)

Any problems, let me know.

Cheers,
Chris