Parent task to keep track of issues and schedule of superset upgrades.
Current version deployed: `0.26.3`
Outstanding issues:
* From version 0.28.1 onward Superset requires Python 3.6, ~~a version not present in Debian Stretch (max 3.5)~~. The SRE team introduced a special apt component to have Python 3.{6,7,8} on stretch with https://gerrit.wikimedia.org/r/#/c/operations/puppet/+/480041.
* Version 0.28.1 introduced several bugs that affect the UI experience, that hopefully should be fixed with 0.29.X. We tried to deploy 0.28.1 but we rolled back after a few hours, so **we are going to skip the update to this version**.
* The Analytics team needs a "staging" version of superset (with a proper database) to test upgrades and possibly allow people to test their dashboards etc.. before the upgrade becomes the current version of superset.wikimedia.org.
Superset releases: https://github.com/apache/incubator-superset/releases