Pytest-docker

Breaking changes:

- Default command changed from `docker-compose` to `docker compose`, so the V2
is the default one.

Chore:

- Set dependency on `attrs` to be the same as in `pytest`

Breaking changes:

- Default behavior is not to install `docker-compose` at all when
installing `pytest-docker` with PIP. Use the `docker-compose-v1` extra.

Feat:

- Add support for Docker Compose v2 via a new pytest fixture,
`docker_compose_command` that should return `docker compose`.

Feat:

- In get_docker_ip(), if `DOCKER_HOST` is using the `unix:` scheme then return "127.0.0.1"

Changes:

- Add `docker_setup` fixture to allow custom setup actions for docker-compose
(contributed by raddessi)

Changes:

- Add support for `pytest` v7 (contributed by skshetry)