Allow for multiple node containers

Merge pull request #17 from Osedea/multi-nodes

Added config for multiple node containers, fixes #13

Node version & reverse proxy port & non-root user

• Fix not being able to use a node version other than latest
• Reverse proxy port can now be customized
• The node app is now ran by a non-root user

Barebones

Working Node Mysql and NGINX containers, settings can be overwritten through a docker-compose.override.yml file.