support custom Redis TLS certs

[vlinkz]

Is your feature request related to a problem? Please describe. I would like to use Redis with https within a vpc, but need a way to add a custom cert used by my redis instance.

Describe the solution you'd like Add support for REDIS_CA_CERT env var.

Describe alternatives you've considered I could either not use TLS (doesn't matter as much within a vpc), or use some custom hook to modify the ca certificates of the container.

Additional context Specifically I'm trying to use helm to deploy ld-relay