MB-100: added swap reb sanity test

Change-Id: I4d83683dc6bf6fc5ccfc82c9972f2e000cdc7aca
Reviewed-on: http://review.couchbase.org/29442
Reviewed-by: Ronnie Sun <ronnie@couchbase.com>
Tested-by: Ronnie Sun <ronnie@couchbase.com>