Moves the airflow sceduler to a container in the airflow-worker
statefulset so that its version lifecycle matches that of the worker.
Leaves the stand-alone scheduler in place to support upgradability from
prior installations that included a standalone scheduler. New
installations are advised to turn off the scheduler template from
rendering using the values.yaml flag.
This is an attempt to make disruptive upgrades to airflow less impactful
to a "update_site" action from Shipyard.
Additionally this removes the template for airflow-flower, which is not in use.
Change-Id: I0608793ee6aba1eb3ce0f5e9567655287014a0ca
Bryan Strassner