services.tutorial.depends_on contains an invalid type, it should be an array

[danielvillalbamota]

I have found an error in the docker-compose.yml where docker-compose v3 expects a list in the tutorial.depends_on:

The current docker-compose.yml have:

depends_on:
    keyrock:
        condition: service_started
    orion:
         condition: service_started

and I have solved it with

depends_on:
    - keyrock
    - orion

I can PR this, but I do not know if it requires maintaining the "condition" as a health check that I do not know how to implement.

[jason-fox]

Raise as a PR and I can review and merge

[danielvillalbamota]

Done: #9