Fix IP addresses

[josibake]

Currently, we still have a method that randomly generates a fake IP address if Tank._ipv4 is None. To get around this, I'm waiting for the pods to spin up and then getting the IP and setting it on the tank, which is pretty gross and will be super slow when spinning up 100s of nodes. We should move all the IP functions into the abstract base class , and grab the IP directly from the container when we need it (same as we were doing in docker land).

[willcl-ark]

I think this would be moot with #303

What did you want IP addresses for? We using hostnames now yo!

[willcl-ark]

Closing as we use hostnames externally and patches on bitcoind