There are two Docker container images defined here
- 
base - it's your usual ubuntu upstart image, with the twist that it's set up to make SSH connections very smooth for automation. Meaning, insecure :) Be careful not to use this image anywhere where network security counts even a little bit! You've been warned. 
- 
host - it's built on top of base, adding ansibleandtestinfra. This is the image you want to use for the host that will run playbooks and tests.
The tests folder contains a sample test arrangement which just makes sure that a host container can transparently connect to another base container. More guidance on setting up playbook runs and tests may come in the near future.