diff --git a/vendor/github.com/go-redis/redis/v8/pubsub.go b/vendor/github.com/go-redis/redis/v8/pubsub.go
new file mode 100644
index 0000000..c56270b
--- /dev/null
+++ b/vendor/github.com/go-redis/redis/v8/pubsub.go
@@ -0,0 +1,629 @@
+package redis
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-redis/redis/v8/internal"
+	"github.com/go-redis/redis/v8/internal/pool"
+	"github.com/go-redis/redis/v8/internal/proto"
+)
+
+const (
+	pingTimeout     = time.Second
+	chanSendTimeout = time.Minute
+)
+
+var errPingTimeout = errors.New("redis: ping timeout")
+
+// PubSub implements Pub/Sub commands as described in
+// http://redis.io/topics/pubsub. Message receiving is NOT safe
+// for concurrent use by multiple goroutines.
+//
+// PubSub automatically reconnects to Redis Server and resubscribes
+// to the channels in case of network errors.
+type PubSub struct {
+	opt *Options
+
+	newConn   func(ctx context.Context, channels []string) (*pool.Conn, error)
+	closeConn func(*pool.Conn) error
+
+	mu       sync.Mutex
+	cn       *pool.Conn
+	channels map[string]struct{}
+	patterns map[string]struct{}
+
+	closed bool
+	exit   chan struct{}
+
+	cmd *Cmd
+
+	chOnce sync.Once
+	msgCh  chan *Message
+	allCh  chan interface{}
+	ping   chan struct{}
+}
+
+func (c *PubSub) String() string {
+	channels := mapKeys(c.channels)
+	channels = append(channels, mapKeys(c.patterns)...)
+	return fmt.Sprintf("PubSub(%s)", strings.Join(channels, ", "))
+}
+
+func (c *PubSub) init() {
+	c.exit = make(chan struct{})
+}
+
+func (c *PubSub) connWithLock(ctx context.Context) (*pool.Conn, error) {
+	c.mu.Lock()
+	cn, err := c.conn(ctx, nil)
+	c.mu.Unlock()
+	return cn, err
+}
+
+func (c *PubSub) conn(ctx context.Context, newChannels []string) (*pool.Conn, error) {
+	if c.closed {
+		return nil, pool.ErrClosed
+	}
+	if c.cn != nil {
+		return c.cn, nil
+	}
+
+	channels := mapKeys(c.channels)
+	channels = append(channels, newChannels...)
+
+	cn, err := c.newConn(ctx, channels)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.resubscribe(ctx, cn); err != nil {
+		_ = c.closeConn(cn)
+		return nil, err
+	}
+
+	c.cn = cn
+	return cn, nil
+}
+
+func (c *PubSub) writeCmd(ctx context.Context, cn *pool.Conn, cmd Cmder) error {
+	return cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
+		return writeCmd(wr, cmd)
+	})
+}
+
+func (c *PubSub) resubscribe(ctx context.Context, cn *pool.Conn) error {
+	var firstErr error
+
+	if len(c.channels) > 0 {
+		firstErr = c._subscribe(ctx, cn, "subscribe", mapKeys(c.channels))
+	}
+
+	if len(c.patterns) > 0 {
+		err := c._subscribe(ctx, cn, "psubscribe", mapKeys(c.patterns))
+		if err != nil && firstErr == nil {
+			firstErr = err
+		}
+	}
+
+	return firstErr
+}
+
+func mapKeys(m map[string]struct{}) []string {
+	s := make([]string, len(m))
+	i := 0
+	for k := range m {
+		s[i] = k
+		i++
+	}
+	return s
+}
+
+func (c *PubSub) _subscribe(
+	ctx context.Context, cn *pool.Conn, redisCmd string, channels []string,
+) error {
+	args := make([]interface{}, 0, 1+len(channels))
+	args = append(args, redisCmd)
+	for _, channel := range channels {
+		args = append(args, channel)
+	}
+	cmd := NewSliceCmd(ctx, args...)
+	return c.writeCmd(ctx, cn, cmd)
+}
+
+func (c *PubSub) releaseConnWithLock(
+	ctx context.Context,
+	cn *pool.Conn,
+	err error,
+	allowTimeout bool,
+) {
+	c.mu.Lock()
+	c.releaseConn(ctx, cn, err, allowTimeout)
+	c.mu.Unlock()
+}
+
+func (c *PubSub) releaseConn(ctx context.Context, cn *pool.Conn, err error, allowTimeout bool) {
+	if c.cn != cn {
+		return
+	}
+	if isBadConn(err, allowTimeout) {
+		c.reconnect(ctx, err)
+	}
+}
+
+func (c *PubSub) reconnect(ctx context.Context, reason error) {
+	_ = c.closeTheCn(reason)
+	_, _ = c.conn(ctx, nil)
+}
+
+func (c *PubSub) closeTheCn(reason error) error {
+	if c.cn == nil {
+		return nil
+	}
+	if !c.closed {
+		internal.Logger.Printf(c.getContext(), "redis: discarding bad PubSub connection: %s", reason)
+	}
+	err := c.closeConn(c.cn)
+	c.cn = nil
+	return err
+}
+
+func (c *PubSub) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.closed {
+		return pool.ErrClosed
+	}
+	c.closed = true
+	close(c.exit)
+
+	return c.closeTheCn(pool.ErrClosed)
+}
+
+// Subscribe the client to the specified channels. It returns
+// empty subscription if there are no channels.
+func (c *PubSub) Subscribe(ctx context.Context, channels ...string) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	err := c.subscribe(ctx, "subscribe", channels...)
+	if c.channels == nil {
+		c.channels = make(map[string]struct{})
+	}
+	for _, s := range channels {
+		c.channels[s] = struct{}{}
+	}
+	return err
+}
+
+// PSubscribe the client to the given patterns. It returns
+// empty subscription if there are no patterns.
+func (c *PubSub) PSubscribe(ctx context.Context, patterns ...string) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	err := c.subscribe(ctx, "psubscribe", patterns...)
+	if c.patterns == nil {
+		c.patterns = make(map[string]struct{})
+	}
+	for _, s := range patterns {
+		c.patterns[s] = struct{}{}
+	}
+	return err
+}
+
+// Unsubscribe the client from the given channels, or from all of
+// them if none is given.
+func (c *PubSub) Unsubscribe(ctx context.Context, channels ...string) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	for _, channel := range channels {
+		delete(c.channels, channel)
+	}
+	err := c.subscribe(ctx, "unsubscribe", channels...)
+	return err
+}
+
+// PUnsubscribe the client from the given patterns, or from all of
+// them if none is given.
+func (c *PubSub) PUnsubscribe(ctx context.Context, patterns ...string) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	for _, pattern := range patterns {
+		delete(c.patterns, pattern)
+	}
+	err := c.subscribe(ctx, "punsubscribe", patterns...)
+	return err
+}
+
+func (c *PubSub) subscribe(ctx context.Context, redisCmd string, channels ...string) error {
+	cn, err := c.conn(ctx, channels)
+	if err != nil {
+		return err
+	}
+
+	err = c._subscribe(ctx, cn, redisCmd, channels)
+	c.releaseConn(ctx, cn, err, false)
+	return err
+}
+
+func (c *PubSub) Ping(ctx context.Context, payload ...string) error {
+	args := []interface{}{"ping"}
+	if len(payload) == 1 {
+		args = append(args, payload[0])
+	}
+	cmd := NewCmd(ctx, args...)
+
+	cn, err := c.connWithLock(ctx)
+	if err != nil {
+		return err
+	}
+
+	err = c.writeCmd(ctx, cn, cmd)
+	c.releaseConnWithLock(ctx, cn, err, false)
+	return err
+}
+
+// Subscription received after a successful subscription to channel.
+type Subscription struct {
+	// Can be "subscribe", "unsubscribe", "psubscribe" or "punsubscribe".
+	Kind string
+	// Channel name we have subscribed to.
+	Channel string
+	// Number of channels we are currently subscribed to.
+	Count int
+}
+
+func (m *Subscription) String() string {
+	return fmt.Sprintf("%s: %s", m.Kind, m.Channel)
+}
+
+// Message received as result of a PUBLISH command issued by another client.
+type Message struct {
+	Channel      string
+	Pattern      string
+	Payload      string
+	PayloadSlice []string
+}
+
+func (m *Message) String() string {
+	return fmt.Sprintf("Message<%s: %s>", m.Channel, m.Payload)
+}
+
+// Pong received as result of a PING command issued by another client.
+type Pong struct {
+	Payload string
+}
+
+func (p *Pong) String() string {
+	if p.Payload != "" {
+		return fmt.Sprintf("Pong<%s>", p.Payload)
+	}
+	return "Pong"
+}
+
+func (c *PubSub) newMessage(reply interface{}) (interface{}, error) {
+	switch reply := reply.(type) {
+	case string:
+		return &Pong{
+			Payload: reply,
+		}, nil
+	case []interface{}:
+		switch kind := reply[0].(string); kind {
+		case "subscribe", "unsubscribe", "psubscribe", "punsubscribe":
+			// Can be nil in case of "unsubscribe".
+			channel, _ := reply[1].(string)
+			return &Subscription{
+				Kind:    kind,
+				Channel: channel,
+				Count:   int(reply[2].(int64)),
+			}, nil
+		case "message":
+			switch payload := reply[2].(type) {
+			case string:
+				return &Message{
+					Channel: reply[1].(string),
+					Payload: payload,
+				}, nil
+			case []interface{}:
+				ss := make([]string, len(payload))
+				for i, s := range payload {
+					ss[i] = s.(string)
+				}
+				return &Message{
+					Channel:      reply[1].(string),
+					PayloadSlice: ss,
+				}, nil
+			default:
+				return nil, fmt.Errorf("redis: unsupported pubsub message payload: %T", payload)
+			}
+		case "pmessage":
+			return &Message{
+				Pattern: reply[1].(string),
+				Channel: reply[2].(string),
+				Payload: reply[3].(string),
+			}, nil
+		case "pong":
+			return &Pong{
+				Payload: reply[1].(string),
+			}, nil
+		default:
+			return nil, fmt.Errorf("redis: unsupported pubsub message: %q", kind)
+		}
+	default:
+		return nil, fmt.Errorf("redis: unsupported pubsub message: %#v", reply)
+	}
+}
+
+// ReceiveTimeout acts like Receive but returns an error if message
+// is not received in time. This is low-level API and in most cases
+// Channel should be used instead.
+func (c *PubSub) ReceiveTimeout(ctx context.Context, timeout time.Duration) (interface{}, error) {
+	if c.cmd == nil {
+		c.cmd = NewCmd(ctx)
+	}
+
+	cn, err := c.connWithLock(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	err = cn.WithReader(ctx, timeout, func(rd *proto.Reader) error {
+		return c.cmd.readReply(rd)
+	})
+
+	c.releaseConnWithLock(ctx, cn, err, timeout > 0)
+	if err != nil {
+		return nil, err
+	}
+
+	return c.newMessage(c.cmd.Val())
+}
+
+// Receive returns a message as a Subscription, Message, Pong or error.
+// See PubSub example for details. This is low-level API and in most cases
+// Channel should be used instead.
+func (c *PubSub) Receive(ctx context.Context) (interface{}, error) {
+	return c.ReceiveTimeout(ctx, 0)
+}
+
+// ReceiveMessage returns a Message or error ignoring Subscription and Pong
+// messages. This is low-level API and in most cases Channel should be used
+// instead.
+func (c *PubSub) ReceiveMessage(ctx context.Context) (*Message, error) {
+	for {
+		msg, err := c.Receive(ctx)
+		if err != nil {
+			return nil, err
+		}
+
+		switch msg := msg.(type) {
+		case *Subscription:
+			// Ignore.
+		case *Pong:
+			// Ignore.
+		case *Message:
+			return msg, nil
+		default:
+			err := fmt.Errorf("redis: unknown message: %T", msg)
+			return nil, err
+		}
+	}
+}
+
+// Channel returns a Go channel for concurrently receiving messages.
+// The channel is closed together with the PubSub. If the Go channel
+// is blocked full for 30 seconds the message is dropped.
+// Receive* APIs can not be used after channel is created.
+//
+// go-redis periodically sends ping messages to test connection health
+// and re-subscribes if ping can not not received for 30 seconds.
+func (c *PubSub) Channel() <-chan *Message {
+	return c.ChannelSize(100)
+}
+
+// ChannelSize is like Channel, but creates a Go channel
+// with specified buffer size.
+func (c *PubSub) ChannelSize(size int) <-chan *Message {
+	c.chOnce.Do(func() {
+		c.initPing()
+		c.initMsgChan(size)
+	})
+	if c.msgCh == nil {
+		err := fmt.Errorf("redis: Channel can't be called after ChannelWithSubscriptions")
+		panic(err)
+	}
+	if cap(c.msgCh) != size {
+		err := fmt.Errorf("redis: PubSub.Channel size can not be changed once created")
+		panic(err)
+	}
+	return c.msgCh
+}
+
+// ChannelWithSubscriptions is like Channel, but message type can be either
+// *Subscription or *Message. Subscription messages can be used to detect
+// reconnections.
+//
+// ChannelWithSubscriptions can not be used together with Channel or ChannelSize.
+func (c *PubSub) ChannelWithSubscriptions(ctx context.Context, size int) <-chan interface{} {
+	c.chOnce.Do(func() {
+		c.initPing()
+		c.initAllChan(size)
+	})
+	if c.allCh == nil {
+		err := fmt.Errorf("redis: ChannelWithSubscriptions can't be called after Channel")
+		panic(err)
+	}
+	if cap(c.allCh) != size {
+		err := fmt.Errorf("redis: PubSub.Channel size can not be changed once created")
+		panic(err)
+	}
+	return c.allCh
+}
+
+func (c *PubSub) getContext() context.Context {
+	if c.cmd != nil {
+		return c.cmd.ctx
+	}
+	return context.Background()
+}
+
+func (c *PubSub) initPing() {
+	ctx := context.TODO()
+	c.ping = make(chan struct{}, 1)
+	go func() {
+		timer := time.NewTimer(time.Minute)
+		timer.Stop()
+
+		healthy := true
+		for {
+			timer.Reset(pingTimeout)
+			select {
+			case <-c.ping:
+				healthy = true
+				if !timer.Stop() {
+					<-timer.C
+				}
+			case <-timer.C:
+				pingErr := c.Ping(ctx)
+				if healthy {
+					healthy = false
+				} else {
+					if pingErr == nil {
+						pingErr = errPingTimeout
+					}
+					c.mu.Lock()
+					c.reconnect(ctx, pingErr)
+					healthy = true
+					c.mu.Unlock()
+				}
+			case <-c.exit:
+				return
+			}
+		}
+	}()
+}
+
+// initMsgChan must be in sync with initAllChan.
+func (c *PubSub) initMsgChan(size int) {
+	ctx := context.TODO()
+	c.msgCh = make(chan *Message, size)
+	go func() {
+		timer := time.NewTimer(time.Minute)
+		timer.Stop()
+
+		var errCount int
+		for {
+			msg, err := c.Receive(ctx)
+			if err != nil {
+				if err == pool.ErrClosed {
+					close(c.msgCh)
+					return
+				}
+				if errCount > 0 {
+					time.Sleep(100 * time.Millisecond)
+				}
+				errCount++
+				continue
+			}
+
+			errCount = 0
+
+			// Any message is as good as a ping.
+			select {
+			case c.ping <- struct{}{}:
+			default:
+			}
+
+			switch msg := msg.(type) {
+			case *Subscription:
+				// Ignore.
+			case *Pong:
+				// Ignore.
+			case *Message:
+				timer.Reset(chanSendTimeout)
+				select {
+				case c.msgCh <- msg:
+					if !timer.Stop() {
+						<-timer.C
+					}
+				case <-timer.C:
+					internal.Logger.Printf(
+						c.getContext(),
+						"redis: %s channel is full for %s (message is dropped)",
+						c,
+						chanSendTimeout,
+					)
+				}
+			default:
+				internal.Logger.Printf(c.getContext(), "redis: unknown message type: %T", msg)
+			}
+		}
+	}()
+}
+
+// initAllChan must be in sync with initMsgChan.
+func (c *PubSub) initAllChan(size int) {
+	ctx := context.TODO()
+	c.allCh = make(chan interface{}, size)
+	go func() {
+		timer := time.NewTimer(pingTimeout)
+		timer.Stop()
+
+		var errCount int
+		for {
+			msg, err := c.Receive(ctx)
+			if err != nil {
+				if err == pool.ErrClosed {
+					close(c.allCh)
+					return
+				}
+				if errCount > 0 {
+					time.Sleep(100 * time.Millisecond)
+				}
+				errCount++
+				continue
+			}
+
+			errCount = 0
+
+			// Any message is as good as a ping.
+			select {
+			case c.ping <- struct{}{}:
+			default:
+			}
+
+			switch msg := msg.(type) {
+			case *Subscription:
+				c.sendMessage(msg, timer)
+			case *Pong:
+				// Ignore.
+			case *Message:
+				c.sendMessage(msg, timer)
+			default:
+				internal.Logger.Printf(c.getContext(), "redis: unknown message type: %T", msg)
+			}
+		}
+	}()
+}
+
+func (c *PubSub) sendMessage(msg interface{}, timer *time.Timer) {
+	timer.Reset(pingTimeout)
+	select {
+	case c.allCh <- msg:
+		if !timer.Stop() {
+			<-timer.C
+		}
+	case <-timer.C:
+		internal.Logger.Printf(
+			c.getContext(),
+			"redis: %s channel is full for %s (message is dropped)", c, pingTimeout)
+	}
+}