localtest: Use docker invocation as per current instructions (#3906)
localtest: Use docker invocation as per current instructions (#3906)

In order to get DinD 'overlay2' support working, the parent
container needs a non-COW filesystem for the Docker Root Directory.
Allocating a host volume to the parent container exposes an
'ext4' (or other) filesystem which will allow the DinD instance
to setup 'overlay2' support correctly.

In addition, adding a volume for the hosts /lib/modules assists with
certain `sysctl` updates.

REANNZ/faucet,anarkiwi/faucet,faucetsdn/faucet,mwutzke/faucet,REANNZ/faucet,faucetsdn/faucet,mwutzke/faucet,anarkiwi/faucet