Npm warning when installing Roots globally (graceful-fs@3.0.8)

[ryanjbonnell]

When installing Roots globally, npm throws the following warning message:

$ npm install roots -g

npm WARN deprecated graceful-fs@3.0.8: graceful-fs version 3 and before will fail on newer node releases. Please update to graceful-fs@^4.0.0 as soon as possible.

This message is shown during the installation of the latest version of Roots, v4.0.1.

I'm running Node.js v4.2.1, Npm v3.8.6 and Roots v4.0.1.

$ node -v && npm -v && roots -v
v4.2.1
3.8.6
4.0.1