* docker_swarm_service tests: use 'resolve_image: no' to avoid registry lookup if image is up-to-date.
* Improve docker_node performance: don't sleep after last try.
* Fix version checks in tests
* Set minimum version to 2.0.2
* Networks can only be updated >= docker-py 2.7
* Constraints require docker-py 2.4.0
* Healthchecks require docker-py 2.6.0
* Properly run tests different docker_py_versions
* Add changelog fragment
* Specify lowest version on placement.constraints
* Fix running new tests on older docker-py
* Handle different hosts formats returned by docker
* FIx test naming
* Quote str options
* secrets options require docker-py 2.4.0
