Replace Caddy with Nginx

[ObadaS]

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

Manual Intervention

There are some new environment variable that will be needed in the .env file

HTTPS=False # Or True
RATE_LIMIT=5

If your DOMAIN_NAME contains : you will need to remove it.
For example, localhost:80 becomes localhost

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