Fix error with default enviroment values under Kubernetes

[scottslowe]

In version 0.5 of the flask-web-svc application, I added some sane defaults for environment variables that should make the application work more "out of the box" with cluster orchestrators like Docker Swarm and Kubernetes. However, there seems to be an issue with deploying the application onto Kubernetes that can only be fixed by explicitly providing environment variable values in the Kubernetes YAML files. I need to fix this so that the default values will work as expected.