Bump lein version to 1.7.0-SNAPSHOT.
Bump lein version to 1.7.0-SNAPSHOT.

cloudControl/buildpack-clojure,jkutner/heroku-buildpack-lein,heroku/heroku-buildpack-clojure,heroku/heroku-buildpack-clojure,mstine/heroku-buildpack-clojure,nvbn/heroku-buildpack-clojure,cedricpineau/heroku-buildpack-clojure-phantomjs