Feature: Allow for Hosts to change IP (kafka-rolling-restart)

[simplesteph]

I have my Kafka cluster in the cloud, and I have two kinds of reboot:

• A soft reboot, which is just restarting my brokers
• A hard reboot, which terminates EC2 instances, and wait for new ones to come up (using a task, thanks for the doc!)

With the hard reboot, because the IP changes and the connection is terminated, the ssh Connection object will fail on the start_kafka command.

So we need a new SSH connection to be instantiated before start_kafka command is executed to ensure we execute it against the right host.