node @7 -> 8 update

Use Node version manager:For development systems you may test different versions so you may want to switch between versions on demand. This is possible using the nvm version manager. This allows you to try out your code in different versions and find problems.Install it using the script:$ curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.2/install.sh | bashThen you may directly use..

2018.08.08