packaging: add keys for dependencies repo

Added gpgkey url to depencencies repositories.
Without a gpgkey, gpg validation fails unless original
repository -release package is also installed.

Change-Id: I210a48b180130e8017d5dd8d67e5c90e0c824fa7
Reported-By: Jorick Astrego <j.astrego@netbulae.eu>
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>