Update from v10 to v13 of bitnami's redis chart, as it should not contain
breaking changes. Adding REDIS_RECONNECT_ATTEMPTS which defaulted to 10
and is now set to 40, which should result in retrying at least 25 minutes
before returning a failure
Prior to this, the only way to set the image tag was by modifying the
appVersion param of the chart itself. This made it impossible to use a
non-default image version.
