Certificate management changes

[litch]

Hi there - we (voltage.cloud) have tried (and customers have tried) to use this library to interface with our hosted nodes. We run lots of LND nodes, and internally are big Rust fans.

This library is currently not compatible with using a valid (not self-signed) cert chain, but I've been able to do some workarounds to make it seem like it'll work.

I'm planning on cleaning that logic up, and adding some automagic for that (maybe this will address #1). And yeah, just saying hi, thanks for making this library (that TLS stuff seems like such a challenge), and look out for some contributions!

[Kixunil]

I'm very happy to hear that! Yes, this looks like a duplicate of #1 but I don't mind since you offered a PR. :) Looking forward to it!