Add vendor/ directory with .gitkeep file
Add vendor/ directory with .gitkeep file

At present the deployment process is trying to symlink a bundle
directory into this dir on deploy, but as vendor/ does not exist the
process fails, meaning the bundle is not cached.

This should allow the bundle to be cached between deploys, which should
greatly speed up the deployment process.

NSWPlanning/data-verification-tool,NSWPlanning/data-verification-tool,NSWPlanning/data-verification-tool