Database per service pattern

[samuelim01]

Description

Currently all services specify their databases, but on production, they share the full database server without restrictions. Ideally, we would like to implement database-per-service pattern, where data independence is ensured. At the same time, we would like the services to share the same database server, to reduce costs. Hence, we shall enforce these restrictions at the database level using different database users (see this).

Let's,

• Update the database selection to be dynamically configured through environment variables instead of hardcoded.
• Remove username and passwords on the Docker databases. Docker is used for development only and does not require authentication. Fixes Fix mongo docker issues #35.
• Streamline environment files

Checklist

• I have updated documentation
• All tests passing

Screenshots (if applicable)

[McNaBry]

LGTM