vorpal version in package that npm installs different from one in repository

[roboticbit]

I'm noticing that although vantage project on github depends on vorpal 1.11.0, as per its package.json,
the package.json file that is under node_modules/vantage after installing via npm references vorpal 1.0.5. How would it be possible to fix this? Both projects are remarkable btw, many thanks!