Announce the August 2014 build env updates

Here are planned updates to the build environments for August, 2014.

This includes move to Leiningen 2.4.3 as the default; be sure to merge https://github.com/travis-ci/travis-cookbooks/pull/361 before creating the JVM image.
would be nice to have a little bit of a friendlier introduction here, this sounds a bit odd to start off with.