bundle mithril.js

[foucist]

Looks like a great project generator. Elixir is great, and so is Mithril.js. Would be cool to have Mithril.js bundled in this, so that you've got both Mithril on the front and back ;).

You can see a mithril.js & elixir codebase here if you're curious: https://github.com/panoply/sissel