Isolate container from network

[Phil Manser]

I'd like to use Pipelines to run my application's tests isolated from the outside network to ensure no outside service is accidentally invoked. (I know one way I could do this would be to set all configuration for outside services to dummy values, but I'd really like to just isolate the containers from the internet as a whole.)

I know with `docker run` I can specify `--network none` to accomplish this. Is there a way I can do that with Pipelines?