packaging: add jessie codename
packaging: add jessie codename

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@redhat.com>

ceph/teuthology,ktdreyer/teuthology,SUSE/teuthology,dmick/teuthology,dreamhost/teuthology,SUSE/teuthology,ceph/teuthology,robbat2/teuthology,SUSE/teuthology,caibo2014/teuthology,caibo2014/teuthology,dmick/teuthology,dmick/teuthology,ktdreyer/teuthology,robbat2/teuthology,dreamhost/teuthology