[WORK IN PROGRESS] set up continuous integration

[afeld]

Closes #20.

[afeld]

Running into this issue:

https://discuss.circleci.com/t/docker-with-centos7-systemd-container/885

[afeld]

• [ ] Try out Test Kitchen /cc https://github.com/GSA/catalog-deploy/pull/202

[afeld]

• [ ] Simplify this to just do the validations; it's better than nothing, and we can figure out how to run the playbook in CI later

[JJediny]

@afeld found this example that's using docker in circleci to run playbooks https://circleci.com/gh/William-Yeh/ansible-nginx

Approach covered here: https://github.com/kfitzpatrick/ansible-docker-circle

[JJediny]

closed by #40