To prepare for switching to TLS, set up TLS certs for Zookeeper and
all of Nodepool and Zuul, but do not have them connect over TLS yet.
We have observed problems with Kazoo using TLS in production. This
will let us run the ZK quorum using TLS internally, and have Zuul
and Nodepool connect over plaintext while also exposing the TLS
client port so that we can perform some more production tests.
Change-Id: If93b27f5b55be42be1cf6ee23258127fab5ce9ea