modules: add ca-certificates module

This module will extract trust information from the host upon
building.

Based on ca-certificates-2014.2.1-2.fc22.noarch.rpm

Signed-off-by: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
java: depend on ca-certificates

Fixes #400.

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