Scenario:- Update node to the given version ?

Solution:- 

Using nvm:-Node Version Manager

Install nvm 

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash

1. Reopen the terminal
2. Check nvm is installed by typing nvm > enter > it will show nvm commands
3. nvm install Node_Version_i_Want

$ nvm install 8.9.4

Note:- After installing the latest node incase your build fails with error like

Node Sass could not find a binding for your current environment: OS X 64-bit with Node.js 8.x

Solution is simply run the sass build npm rebuild node-sass