Implement Postgres Operator for failover, high-availability, backups, etc.

[philippemnoel]

What Eventually, we'll want to have high availability. To do this with Postgres, there is a tool called Patroni. Citus has native support for it, so I propose we use this since it seems safe to say we'll be using Citus. If we end up not using Citus, we can use Spilo to do this, which is a combination of Postgres+Patroni directly.

Why Offer high availability!

How Citus has native support for Patroni, so we should just use the Citus+Patroni configuration

[philippemnoel]

https://github.com/zalando/patroni/blob/master/docs/kubernetes.rst

[philippemnoel]

https://github.com/CrunchyData/postgres-operator

[philippemnoel]

After some reading, I believe the CrunchyData one is the right decision to use: https://github.com/CrunchyData/postgres-operator

[philippemnoel]

@MauAraujo once we add this, we should add it to the THANKYOU.md file :)

[philippemnoel]

@MauAraujo has done this in the /infrastructure repo