upgrade to 0.6.12 and fix download url
upgrade to 0.6.12 and fix download url

rightscale/cassandra,cassandra-rb/cassandra,rightscale/cassandra,stipple/cassandra_new,cassandra-rb/cassandra,stipple/cassandra_new,cassandra-rb/cassandra,stipple/cassandra_new,stipple/cassandra_new,cassandra-rb/cassandra,rightscale/cassandra