ceph-build:  drop oneiric and fedora17 from build

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>
do_release.sh:  Don't sign rpm packages yet.

Since we are now adding extra rpms to the repo, wait until we
are all done before signing them.  Signing is done in another shell
script later in the pipeline.

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>
sign_and_index_rpm_repo.sh:  New script

This is the last script to run against the rpm repo after any
extra packages are added.  It signs all the rpms in the repo,
then builds an index using creatrepo for the top level directories
such as noarch and x86_64.

Signed-off-by: Gary Lowell  <gary.lowell@inktank.com>