remove packages that just contain files

[matthewmueller]

e.g.

var preact = js.RawFile("./preact.js")

// Render the component
func Render(component jsx.Component) {
    js.Rewrite("$1.render($2, document.body)", preact, component)
}

Turns into:

(function() {
    var preact = js.RawFile("./preact.js")
    return {}
})()