Add SSL config for HTTPS

[jcohenho]

I think this will partly solve https://github.com/claffin/cloudproxy/issues/3.

The cert.pem and key.pem can be generated with mkcert

Tbh I have no idea what I'm doing, any suggestions would be much appreciated. I tested this locally and I have the docker image running on https now.

Edit: I suppose mkcert is only good for https in local environments. My goal is to deploy Cloudproxy to an AWS ec2 instance and make it accessible via HTTPS, and ensure communication between the cloudproxy server and proxy servers are done via HTTPS as well.

[claffin]

I think the best approach would be to deploy cloudproxy behind an nginx reverse proxy, then have nginx provision a SSL cert via Lets Encrypt. I'm reluctant to have cloudproxy to manage the SSL cert.