Fix problems with docker-compose

[stoopidJSON]

User Story

As a developer
I'd like to have a working docker-compose.yaml
So that I can quickly launch the full stack app locally

Acceptance Criteria

• docker-compose up will launch the Dockerfile included in the repo, and a PostgreSQL container
• the containers work together and the API is accessible from localhost

Notes

Currently, it looks like PostgreSQL is broadcasting on 0.0.0.0 which may be correct, but networking isn't setup properly. This is likely a quick fix.