ENYO-826: first `npm pack` that produces a working Ares

- `npm pack` only works consistently on Linux.
  https://github.com/isaacs/npm/issues/2619
- add instructions for integration on a build server
- cleanup to get closer of a normal NPM folder hierarchy (with proper
  `package.json` content).

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>