Find a safe way to store the database credentials

Design

For now, the database credentials are hard-coded in clear. This is highly unsafe but manageable for now, but let's quickly find a safer solution.

Ideas

• Environment variable
• CI job

Tasks

• Create a proper preference reading system (from yml files)
• Move Blinkink's Bip credentials to another repository, private
• Update CI jobs so the config folder on tech is managed by the other repo's CI