CBQE-2397: n1ql conditional fns tests

Change-Id: I77afc950794b30d643bc552de00c0f89e252506b
Reviewed-on: http://review.couchbase.org/41229
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>
Tested-by: buildbot <build@couchbase.com>