make yoctolib_js a node module

i think this is all that's required.

you may want to change the package version to 1.01.12553

note that, if you accept this pull, you will need to publish this as a module so folks can find it easily. here is the tl;dr

  https://gist.github.com/coolaj86/1318304

if you want a longer description:

  https://npmjs.org/doc/developers.html

enjoy!