Upgrade Elixir and switch to Ubuntu

Turns out 1.0.2 came out and I totally missed it.

Also, unfortunately everyone uses Ubuntu and since sometimes things
break when deploying apps on to another distro (locations of C libraries
can be different), it makes the most sense to use a more common, pleb
distro (also sux that EC2 basically is all like "yo u want ubuntu or our
thing otherwise fuk u")