Download the latest nginx config files from the nginx repo during the build process

[konklone]

Let's bake the nginx files into fisma-ready/nginx, instead of here, and then download them during the build process. (The build process already requires an internet connection.)

• I need to move the nginx config files out of 18f/tls-standards and into fisma-ready/nginx first.

[seanherron]

Is there even a reason to bake it in to the AMI build process? Wouldn't you just pull the config from fisma-ready/nginx if you wanted to install nginx? There may be cases when using the AMI that you don't want a webserver installed.

[NoahKunin]

For the current sprint, nginx will be installed manually. Next sprint, nginx installation can occur via passing a parameter if the intended EC2 instance is to web serve.