Add setup.sh and demo.sh scripts #12

#10 raised a question about getting the Consul DNS name.

Ideally we'd like to eliminate use of the --link to Consul in the main docker-compose.yml and use DNS discovery instead. To make this easier, a setup.sh script like the one in https://github.com/autopilotpattern/couchbase would be a convenient addition that could write out the _env file with the DNS name for the Consul service.

The demo.sh script` is not strictly required, but it automatically opens up the web web browser to the correct locations, making for a convenient demo.