Fix Cassandra::Mock to also accept start_key just like the real thing
Fix Cassandra::Mock to also accept start_key just like the real thing

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