add large scale n1ql test

Change-Id: I9d45ee9d9e77b1e8b1ee3cf6d95ba7a6f60e2fd3
Reviewed-on: http://review.couchbase.org/37372
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Pavel Paulau <pavel.paulau@gmail.com>