adding a cluster spec  with titan servers & hera client
adding a cluster spec  with titan servers & hera client

Change-Id: I67d5f262093e6c5ffeece1a1a0908b4e3a6cfb9c
Reviewed-on: http://review.couchbase.org/c/perfrunner/+/138349
Reviewed-by: <7c5437523872fffef04ef9d4aaffcc0ca27fba16@gmail.com>
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>

couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner,couchbase/perfrunner