add sample systemd unit config files

This adds two fairly basic systemd unit configuration files, setting
up the GS as a service (dependent on rethinkdb). The difference
between the "normal" one and the sample for the Vagrant environment is
merely the path of the GS package, and the user to run the GS as.
add sample local config file for production environments
add simplistic deployment script

A very simple bash script deployment system. deploy.sh is meant to be
run via a Jenkins job (which sets the necessary environment variables).
It rsyncs the GS package to the target system, and invokes
deploy-remote.sh there to replace the old version with the new one,
and restart the GS service.
Merge pull request #32 from yelworc/deployment

deployment scripts