Python-on-whales

* When the Docker CLI is not installed, now the client 20.10.5 is downloaded instead of the 19.03.10.
* Some refactoring, cleaning up the models and separate them from the rest of the codebase.
* Improved the docs (containers and downloading the Docker CLI).

v.14.3
* Fix a bug when parsing the empty response of Compose with a recent version that doesn't have the experimental warning.

Fixed a bug that was triggered when parsing the system info output

* Fixed a bug occuring when pasing the response of the docker daemon for a task without the node id.

* Added some methods for Stacks
* Better docs: A diagram was added.
* Fixed a parsing bug on tasks and services.

* Fixed a bug preventing the parsing of services.

Added multiple commands:
* `docker.compose.ps()`
* `docker.swarm.unlock()`
* `docker.swarm.unlock_key()`