Handle userns security
Handle userns security

- Adds `--userns=host` when `userns-remap` is set

Signed-off-by: Maxwell Bloch <bb3d5eba9e02a6215cd4abf6e94d44f3bdc3ad8e@live.com>

thaJeztah/compose,vdemeester/compose,thaJeztah/compose,vdemeester/compose