Publish version 1.3.3 to npm (feature: multiple outputs per file)

[YetAnotherMinion]

The changes provided by @folkertdev on #11 are newer than version published on npm. Would you mind publishing an updated version using the current master to npm?

[YetAnotherMinion]

It has been almost a year, I am going to fork elm-static-html now. I want to add Elm 0.19 support anyway.