RedisMock set method expire time value is in seconds

[kronostof]

The set method signature on RedisMock seems to be wrong and store ttl in second.

However set should support milliseconds for ttl definition.

Proposal

public function set($key, $value, $options = null, $ttl = null)
{
    /**
     * Per https://redis.io/commands/set#options
     * EX seconds -- Set the specified expire time, in seconds.
     * PX milliseconds -- Set the specified expire time, in milliseconds.
     * NX -- Only set the key if it does not already exist.
     * XX -- Only set the key if it already exist.
     */
    if (!is_null($options) && !in_array($options, ['ex', 'px', 'nx', 'xx'])) {
        $this->returnPipedInfo('(error) ERR syntax error');
    }
    if ('nx'=== $options && $this->get($key)) {
        return $this->returnPipedInfo(0);
    }
    if ('xx' === $options && !$this->get($key)) {
        return $this->returnPipedInfo(0);
    }

    if ($options === 'ex') {
        $ttl = $ttl;
    } elseif ($options === 'px') {
        $ttl = $ttl / 1000;
    }

    self::$dataValues[$this->storage][$key] = $value;
    self::$dataTypes[$this->storage][$key] = 'string';

    if (!is_null($ttl)) {
        self::$dataTtl[$this->storage][$key] = microtime(true) + $ttl;
    }

As it will be impacted, We should update RedisSessionHandler, and check that ttl resolution is compatible with symfony session resolution