Revert "Use wget for downloading instead of curl."
Revert "Use wget for downloading instead of curl."

This reverts commit 5b4b8c90425d7c809977dd8b46171f68c9bca41d.

Apparently wget isn't available in production (!)

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