The API is just an alternate way of uploading to the site, allowing the manual uploading to be scripted/automated, no packaging involved.
Afaik, Dolby is already working on a true packager, or at the very least is considering it, he'll have to comment on that though.
If you want to completely automate it with as little effort as possible, take a look at BigWigs' packager project:
https://github.com/BigWigsMods/packager.
This can be automated with TravisCI to automatically package and upload for you, an example can be found in the main BigWigs project repo (.travis.yml)