Description
Renames a key.
重命名一个KEY
Parameters
STRING: srckey, the key to rename.
STRING:源KEY，需要改名的KEY
STRING: dstkey, the new name for the key.
STRING:目标KEY，KEY的新名字
Return value
BOOL: TRUE in case of success, FALSE in case of failure.
Example
$redis->set('x', '42');
$redis->rename('x', 'y');
$redis->get('y'); // → 42
$redis->get('x'); // → `FALSE`
