def data_only_container(name, volumes):
info = inspect_container(name)<EOL>if info:<EOL><INDENT>return<EOL><DEDENT>c = _get_docker().create_container(<EOL>name=name,<EOL>image='<STR_LIT>',  <EOL>command='<STR_LIT:true>',<EOL>volumes=volumes,<EOL>detach=True)<EOL>return c<EOL>
create "data-only container" if it doesn't already exist.

We'd like to avoid these, but postgres + boot2docker make
it difficult, see issue #5