* Move tests with docker registry into own target.
* Add docker_login tests.
* Add step which makes sure hello-world:latest is around.
* Make work inside docker container.
* Add dependency.
* Use plaintext password.
* Forgot check_mode.
* Add no_log to avoid double log output in verbose mode.
* Check minimal API and docker-py versions for all docker_* tests.
* Improve docker_swarm creation/destruction for tests.
* Fail when conditions aren't met.
* Don't hardcode address for advertise_addr.
* Add docker_image_facts tests.
* Add basic integration test for docker_volume.
* Add basic docker_image tests.
* Only start test registry when tests are actually run (i.e. not on CentOS 6).
