* General test improvements.
* Adjust tests to older docker-py versions.
* docker_swarm_server_info: work around problems with older docker-py versions
* Bump minimal docker-py version for options network_filters and disk_usage.
* More general test improvements.
* Correct usage of docker_image.
* Put files into output directory.
* Speed up test.
* Remove old check.
* Decreasing docker_swarm requirements.
* Fixing docker-py / docker API version requirements, and some comments.
* Add changelog.
* Only send parameters specified by user to docker daemon.
* Extend labels test: not specifying == keep labels.
* Bump minimally required docker-py version for docker_node and docker_node_facts to 2.4.0.
* Prevent crashing when publish or healthcheck is not provided.
* Similarly to docker_swarm tests, only execute docker_node tests on real VMs and restart docker daemon when tests are done.