* Use an existing secret for the InfluxDB auth

- Sometimes you need to check in the values.yaml in a repo
and you don't want to expose the secrets. With the existingSecret
option you can use and existing kubernetes secret with the keys
`influxdb-user` and `infuxdb-password` to set the corresponding
environment variables in Kapacitor. The keys are the same as the
ones used in the `influxdb-auth` secret created by the InfluxDB
Helm chart.
Signed-off-by: Angelo Fausti <afausti@lsst.org>

* Bump minor version instead
Signed-off-by: Angelo Fausti <afausti@lsst.org>