docker remote host support

[christianwiedemann]

The docker compose transport does not suport a remote host. This would be a nice feature to remove the need to install ssh in a remote docker compose environment. For docker compose 2 it is not possible to add an docker options because the host parameter must be a docker -H compose

Describe the solution you'd like
Add a new configuration option host under key docker and use this host as a -H in shell command.

[christianwiedemann]

See #85

[weitzman]

See #85 for DOCKER_HOST suggestion.

[christianwiedemann]

Hi @weitzman The problem with DOCKER_HOST is that we have different environment with different docker hosts. One for PROD one for test environments. Is it possible to set the environment dynamic before executing a drush command? Or is there any chance to get this merged?