zRange is not work

[youjiawang]

$this->redis->zRange( $key, $start, -1, false ); return null; $this->redis->zRange( $key, $start, -1, TRUE); is not corrent php 7.0.2

[Jerry-Shaw]

@youjiawang This PR moved here, https://github.com/phpredis/phpredis/tree/php7, this branch is working well under php7.