hIncrBy
Description
Increments the value of a member from a hash by a given amount.
根据HASH表的KEY，为KEY对应的VALUE自增参数VALUE。
Parameters
key
member
value: (integer) value that will be added to the member's value
Return value
LONG the new value
Examples
$redis->delete('h');
$redis->hIncrBy('h', 'x', 2); /* returns 2: h[x] = 2 now. */
$redis->hIncrBy('h', 'x', 1); /* h[x] ← 2 + 1. Returns 3 */