Issue under dependencies in package.json for gulp version.

The gulp version in package.json is mentioned as
"gulp": "github:gulpjs/gulp#4.0",

Which throws the below error,

npm ERR! git rev-list -n1 4.0: fatal: ambiguous argument '4.0': unknown revision or path not in the working tree.
npm ERR! git rev-list -n1 4.0: Use '--' to separate paths from revisions, like this:
npm ERR! git rev-list -n1 4.0: 'git <command> [<revision>...] -- [<file>...]'
npm ERR! git rev-list -n1 4.0:

Seems like this should like this,
"gulp": "github:gulpjs/gulp#v4.0.0"

As there is no more a 4.0 tag https://github.com/gulpjs/gulp

Attaching a simple patch for this.