Verify node and npm is compatible

[patocallaghan]

As you can specify a node and npm version in the engines part of the package.json, can this addon be use to warn if an incompatible version is being used?

 "engines": {
   "node": "5.0.0",
   "npm": "3.3.12"
 },

[alexlafroscia]

Would love to open this conversation up. My team has been talking about how to ensure we're all using the same version of Yarn, and something like this could be a really nice solution.

I'm not sure if engines would be the right way to do that, since that is supposed to dictate the version of the runtime that the package supports, but something similar would be a great idea to verify the version of global packages.