Make changes necessary to publish and install with elm-get

These revisions make the repo compatible with elm-get so you will be able to publish with:

    elm-get publish

and users will be able to start using a particular version of it in any directory with

    elm-get install seliopou/elm-d3

They can create files like `Todo.elm` and compile them with:

    elm --make --script="http://d3js.org/d3.v3.min.js" Todo.elm

If they want to use the CSS script, it will be in `elm_dependencies/seliopou-elm-d3/0.1.2/scripts/` or it can be offered as a script they download separately.