We have cross links in our generated libraries that point to this url:
https://googleapis.github.io/gax-nodejs/global.html

It looks like the ref docs for gax are down, which is super weird since they haven't been touched in years (heh, maybe a different problem) and github pages seems to still be enabled on the repo.

This is causing doc tests to fail on all PRs in generated libs:
https://source.cloud.google.com/results/invocations/67570ab1-6007-44ce-8537-2f4964e2f0dd/targets/cloud-devrel%2Fclient-libraries%2Fnodejs%2Fpresubmit%2Fgoogleapis%2Fnodejs-pubsub%2Fnode10%2Fdocs/log