Implement auto ping

[3rd-Eden]

There's a small annoyance with pub/sub and that is if you don't publish frequently enough the connected client might disconnect due to it's configuration in redis. In order to combat this we should be sending frequent ping messages. The timeout can be retrieved by issuing config get timeout in the redis-cli.

We could just send a simple ping packet to redis server or broadcast a ping message over pub/sub channels.