apps: update to latest

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
cloud-init/cassandra: Use debug() for logging

For some reason, output to cout does not show up on EC2 logs. Switch to
debug() until it's sorted out.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>