Use NPM features to ensure correct node version


According to the readme: 
> The sqlite3 module works with Node.js v0.8.x, v0.10.x or v0.11.x (though only v0.11.13 and above).

I propose the engines parameter be updated to be more specific, and that `engineStrict:true` is provided so that the node version should be enforced by npm when running `npm install` (https://www.npmjs.org/doc/files/package.json.html#enginestrict)