Create a new and better way to write out .env files

[epicserve]

• Figure out how to run the setup script without the project running
• Figure out the issue with the project changing the owner of the .env file to root when it is run with Docker
• Figure out how to define variables that other variables depend on, for example:

  POSTGRES_USER=django-base-site
  POSTGRES_DB=django-base-site
  POSTGRES_PASSWORD=**random-password**
  DATABASE_URL=postgres://${POSTGRES_USER}:${POSTGRES_PASSWORD}@db:5432/${POSTGRES_DB}