Upgrate Nodejs version for our jenkins environment

[徐毅]

Hi,


Recently, I have found that our jenkins pipeline for iotdb-website project 
always fail when executing `npm install`. On my computer, it works. Nodejs and 
npm version are:


$ node -v
v10.15.1


$ npm -v
6.4.1


On Apache jenkins, their versions are:
npm ERR! node v6.16.0
npm ERR! npm  v3.10.10


Can anyone help to upgrade nodejs to v10.x.x and npm to 6.x.x for our jenkins 
pipeline?


Thanks
XuYi