Provision docker-machine admin containers

[modius]

Would be nice to have a mechanism to provision (and re-provision) the admin containers that spin up in the docker-workbench.

Perhaps an option to look for a default docker-compose.yml in the working directory or fall back to a default compose within the utility itself:

docker-workbench provision

Or to nominate a specific compose file as needed:

docker-workbench -f mycompose.yml provision

[mjb]

great idea.