webjars packaging of zeptojs v 1.0 per the github release artifact.

Greetings again!

The following pull request brings Webjars Zeptojs 1.0 inline with the pattern followed by recent Webjars using the Wagon plugin to pull from a known artifact source.  The antrun plugin is used to grab just the relevant src files from the Zeptojs zip file.  I can't find a plain amalgamation on the Zeptojs site, so this change will basically only include the contents of the src/ folder from the github release artifact in the provided Webjars destdir.

Let me know if there is anything else you need to accept this.