Update Elixir version
Update Go version
Bump `rust` to version 0.8
Make it compatible with Vagrant 1.4.0
Update `redis` version
Bump `groovy` to 2.2.1
Bump `zeromq` to 4.0.3
Bump `scala` to 2.10.3
Update the `provision` command to reload the $PATH
Bump `gradle` to 1.9