Automate testing and build process

[jordwest]

Restarting server and running tests manually during development is tedious, set up fswatch for re-running tests and restarting server

• Watch for changes, rerun go test
• Watch for changes, build and restart demo server

[jordwest]

No code changes needed, install fswatch and then run

fswatch go test

or

fswatch go run demo/dummy_server.go