Add support for python, R, ruby, js via graalvm-polyglot

[jexp]

See github.com/moxious/magnolia.

http://www.graalvm.org/docs/reference-manual/polyglot/

/cc @moxious

// gu install ruby python R 
// groovy PolyTest1.groovy 
@Grab("org.graalvm.sdk:graal-sdk:1.0.0-rc9")

import org.graalvm.polyglot.*

context = Context.newBuilder().allowAllAccess(true).build()
context.eval("js", "print('Hello JavaScript!');")
context.eval("R", "print('Hello R!');");
context.eval("ruby", "puts 'Hello Ruby!'");
context.eval("python", "print('Hello Python!')");