Support container_name modification

[posixcompliance]

Hi as far as I can tell there is no way to specify the container_name value without manually modifying the following compose file under lib/. I think that this would be a nice feature to include in config/overleaf.rc to allow for multiple toolkit or custom docker-compose.yml files of the main overleaf/overleaf to be deployed to the same docker daemon for testing purposes.

toolkit/lib/docker-compose.base.yml

Line 8 in e8b536c

container_name: sharelatex