Node: install latest version of npm

Developers are often getting unexpected changes in their `package-lock.json` when running `npm install` in their project. This is most of the time caused by developers using different major versions of npm.

To avoid this as much as possible, we should probably enforce the update of npm to the lastest version during the provisioning.

The issue does not name a file, test, or provisioning entry point. Start by locating the Ansible provisioning code that installs Node and npm, then determine how the latest npm version should be enforced during provisioning. Done means provisioning consistently updates npm and no longer leaves developers on differing major versions.

Written by the indexing model from the issue text.