Add support to deploy using Kamal

[EmilioCristalli]

We want to try Kamal to do the deploys using docker and AWS servers.

In this PR we are adding two destinations (staging and production), both sharing the same server, at least for now.
Each destination also has an "accessory" to set up a postgres database in a second server (also shared between both destinations)

You will need an .env.staging and .env.production with these secrets RAILS_MASTER_KEY, DATABASE_URL and POSTGRES_PASSWORD

Steps to set up the servers in AWS:

1. Run this to install docker

sudo apt update
sudo apt install -y docker.io curl git
sudo usermod -a -G docker ubuntu

2. Add any authorized keys for people that need to connect with ssh
3. For the web server run this (needed to auto generate SSL certificates using LetsEncrypt)

mkdir -p /home/ubuntu/letsencrypt && touch /home/ubuntu/letsencrypt/acme.json && chmod 600 /home/ubuntu/letsencrypt/acme.json

4. Enable HTTPS (443) incoming traffic in web instance
5. Enable ports 5432 & 5433 for incoming traffic in DB instance
6. Run kamal setup -d staging (or -d production)

For normal deploys run kamal deploy -d staging.
If env vars change you will have to push them with kamal env push -d staging

[santiagorodriguez96]

Should we also add fing.micarrera.uy too?

[EmilioCristalli]

added in 803422b

[santiagorodriguez96]

I would honestly remove kamal's .sample files if we are not going to use them 🤔

[EmilioCristalli]

removed in 9138f87