Have Heat and Ceilomter use Precise Jenkins slaves

Heat and Ceilometer were using oneiric nodes for all tests. Switch the
default node for these projects to Precise so that only python2.6 jobs
run on Oneiric. Do this to take advantage of the larger number of
Precise slaves.

Change-Id: I282ee3fd2b033875aef25083c74232009d4706a8
Reviewed-on: https://review.openstack.org/19492
Reviewed-by: Julien Danjou <julien@danjou.info>
Reviewed-by: Angus Salkeld <asalkeld@redhat.com>
Reviewed-by: Steve Baker <sbaker@redhat.com>
Reviewed-by: Steven Hardy <shardy@redhat.com>
Reviewed-by: Zane Bitter <zbitter@redhat.com>
Reviewed-by: Jeff Peeler <jpeeler@redhat.com>
Reviewed-by: Doug Hellmann <doug.hellmann@dreamhost.com>
Reviewed-by: Steven Dake <sdake@redhat.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins