Install tgt and iscsi.  Ubuntu needs to also use a version of tgt that
has CEPH_RBD set.
Fixes: 6723
Signed-off-by: Warren Usui <warren.usui@inktank.com>
Merge branch 'wip-chef-tgt-iscsi-wusui'
Add libleveldb1 from ceph-extras.

Signed-off-by: Sandon Van Ness <sandon@inktank.com>