A brief description of the purpose of the changes contained in this PR.

• Replace Caddy with Nginx, allowing us to route every connection through it (like rabbit, minio, postgres) instead of only HTTP(S) connections
• Add anti-scrapping measures
• Add robots.txt file
• Closed all the external ports of the containers except Nginx. Everything must go through Nginx now.
• Made all containers (except Nginx, Django, Compute Worker and Builder) unable to access the outside world.
• Add rate limit

Checklist

• Code review by me
• Hand tested by me
• I'm proud of my work
• Code review by reviewer
• Hand tested by reviewer
• CircleCi tests are passing
• Ready to merge