Use revision 3.0 for memcached in toy-sriram.xml

Change-Id: If8f5b8767f46d944adf91096ba3b06d3d2192dc6
Reviewed-on: http://review.couchbase.org/38974
Reviewed-by: Sriram Ganesan <sriram@couchbase.com>
Tested-by: Sriram Ganesan <sriram@couchbase.com>