Pass argument '--rm' to avoid wkdev-create container name collission

[dpino]

Follow-up to d347129.

Command wkdev-create allows passing argument --rm which stops and removes a container in case it already exists. This can be useful to avoid the container name collission, instead of creating a temporal name for the container and stopping and removing it late.

To avoid the home directory collission, wkdev-create can delete the home directory in case it already exists and create-home was passed as an argument.

[dpino]

I'm not sure about this change. What happens if two processes are running this step simultaneously? Giving an unique name to each container guarantees isolation. Perhaps what it makes sense is to have a wkdev-remove command to remove a container (and home directory) in a clean way.

[TingPing]

I think switching to a tmp dir instead of based on date sounds fine.