Persistent storage to a single MongoDb instance

Only the tracker has a new image in this release.

See k8s-manifests/docker-compose.yaml for the full stack.

Release 2 - Now supports historic tracks

release2

case #19

Release 1

This release is the final code for the images we will be using in the first part of the Kubernetes course. The corresponding Dockerhub images are also tagged release1.

There will be further small releases to illustrate (eg) rolling deployments.

There may be a release2 which is planned to include a persistent storage (using persistentsets) with MongoDb.