Since there have been a few minor but not insignificant changes across
several services its time for a tag update!

General:
- add k8s-node-termination-handler to cordon nodes before preemption,
increasing uptime with nicer failover
- Add podAntiAffinity to spread pods for a service across nodes more
evenly, for several services.

Gitlab and CI:
- Update from 11.10.4 -> 12.2.0
- Add retry for Gitlab's self-deploy, which always used to fail.

README.md:
- Update ubuntu-node-01 OS information
- Re-run VPN performance.
- Add note about pusher/oauth2_proxy