* travis: remove verbose from Swarm race tests

By removing -v our output will be cleaner, but the Travis job still
won't be terminated - due to 'no output for 10 minutes' - as keepalive
.sh produces a log line every 5 minutes.

* travis: extend Swarm race detection to p2p subpackages

As p2p/protocols, p2p/simulations and p2p/testing packages mostly
belong to the Swarm team.