travis: execute cgroup tests
travis: execute cgroup tests

I don't know why they were disabled, but they work fine.

travis-ci: success for travis: execute cgroup tests
Signed-off-by: Andrei Vagin <74c05afa918858348d6db8037d82fa8124870113@openvz.org>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@virtuozzo.com>

eabatalov/criu,eabatalov/criu,eabatalov/criu,eabatalov/criu,eabatalov/criu,eabatalov/criu