Dockerfile security/performance/readability
Dockerfile security/performance/readability

In addition to being prettier and perhaps easier to read, the
Dockerfile does a couple new/different things:

* Uses /srv as the directory to store the node server source files

* Creates the system user "rpnow" to run the node server

* Copies in package.json and runs "npm install" before copying in
  the rest of the source. This makes it so changing files in the
  source (other than package.json) won't cause docker to reinstall
  all the npm packages.

shamblesides/rpnow,shamblesides/rpnow