Use native zip binary instead of node-archiver.

The node-archiver package appears to be unmaintained (judging from github
issue backlog) and generated corrupt archives when the 'store' option is
used.

Simplify the code by just using the system 'zip' binary.

Change-Id: I543e881227db8644da38cddc6dc18014fb0008f1
Merge "Use native zip binary instead of node-archiver."