In the nodejs plugin, there is no way to specify the npm version required

[Leo Arias]

From the dcos-ui project (https://github.com/dcos/dcos-ui):
"Node 4.x and NPM 3.x (and above) are required."

That is not possible with the nodejs plugin. when I use node v4.4.7, npm v2.15.8 is installed. I can use a more recent npm version by using a more recent node engine, but then the server won't start:

ERROR: Node version v6.7.x does not match required version v4.4.x
npm ERR! Linux 4.8.0-19-generic
npm ERR! argv "/snap/dcos-ui/x2/bin/node" "/snap/dcos-ui/x2/bin/npm" "run" "check-env"
npm ERR! node v6.7.0
npm ERR! npm v3.10.3