Initialize with npm init

[mapsam]

It looks like, as of npm 6.1, you can run npm init <initializer> which will be build a project for you. Wonder if we could do this for npm init create-node-cpp-skel?

https://docs.npmjs.com/cli/init

cc @kepta @ian29 @springmeyer @millzpaugh

[springmeyer]

We're modern as can be now after #161