Certbot needs Port 80 accessible on Docker host

[krisdthompson]

For the Certbot HTTP based verification to work, port 80 also needs to be open.

> docker logs iotdash_nginx_1
...
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for iotdash.XXXX.com
nginx: [error] invalid PID number "" in "/run/nginx.pid"
Waiting for verification...
Cleaning up challenges
Deploying Certificate to VirtualHost /etc/nginx/sites-enabled/default
Redirecting all traffic on port 80 to ssl in /etc/nginx/sites-enabled/default

Port 80 must be open to the NGINX host. e.g. validate the Network Security Group if using Microsoft Azure.

Good tip for Setup docs. Add to list of required ports.

[terrillmoore]

@krisdthompson thanks! We'll update this.