Define a DoD for our tasks

As the project is crowing, let's define a baseline DoD for our tasks.

Initially focusing on sprint-level Definition of Done.

Two parts in the project, client side plugin and the server backend with Docker images.

 
DoD
Dashboard:

1. Project builds without errors
2. Tests defined, marked as failed if not implemented
3. Feature ok-ed by Product Owner

Docker images: 

1. Hello world app compiles
2. Any configuration or build changes documented