Add support for using custom TLS certificates e.g. letsencrypt

[x-ji]

For any real production deployment, TLS should be indispensable?

[x-ji]

Or do you tend to put the TLS at the CDN level instead of directly on the Phoenix app etc.

[reachfh]

Yes, I think certs are a requirement for most websites. I plan to add letsencrypt support in the next iteration. I tend to use AWS support in the Application Load Balancer for larger applications. That's another thing I have in the pipeline....