CBQE-281 Test for replication of design document in a cluster

Change-Id: I6f4f38be12f1d4a467b267664ed2408a404092e5
Reviewed-on: http://review.couchbase.org/23935
Reviewed-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>
Tested-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>