Update toy-hhs.xml to fetch couchdb from master instead of specific
revision.

Change-Id: I2ba89d133a5c9116e7d95efced62ca0c81778578
Reviewed-on: http://review.couchbase.org/41385
Reviewed-by: Harsha H S <hhs.couchbase@gmail.com>
Tested-by: Harsha H S <hhs.couchbase@gmail.com>