Adding CA Certificate for RedisBroker

[coding-trees]

2nd part to adding CA certificate support for RedisBroker as described in this issue #129

[coding-trees]

Hi @odacremolbap - let me know if there are any other docs or repos that will need to be updated with information re: CA Certificates. Thanks

[odacremolbap]

Thanks a lot for your PRs @coding-trees
This is looking good.

I asked for a couple of nits.

At one of them I am suggesting to validate that CA Certificate is not informed alongside Skip Verify. That would be done here and would probably look like this:

	if ra.TLSCACertificate != "" && ra.TLSSkipVerify {
		msg = append(msg, "only one of skip verify or CA certificate can be informed")
	}

[coding-trees]

Hi @odacremolbap - Thank you for the review and feedback, I believe I have applied all of the changes you have suggested - if there is anything missing or anything is still kind of "off" please let me know. I don't mind any and all suggestions, feel free to nit pick; just want to make sure the changes are up to snuff.