Enable HTTPS

Use self-signed certificates for development:

```bash
$ openssl genrsa -des3 -passout pass:x -out server.pass.key 2048
...
$ openssl rsa -passin pass:x -in server.pass.key -out server.key
writing RSA key
$ rm server.pass.key
$ openssl req -new -key server.key -out server.csr
...
Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:California
...
A challenge password []:
...
$ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
```

Store `server.crt` and `server.key` in `/etc/sibyl/conf`.