packaging: setup: require answer file on additional hosts

Require the use of an answer file on additional hosts deployment.
Allows to fetch the answer file from the first host
providing its address and root password.

Change-Id: Ie8fd38828422c52c416ad3125c2e39193956d74f
Bug-Url: https://bugzilla.redhat.com/1007422
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>