Fix stdout handling: allow logging before JSON result object

[enolan]

What did you implement:

Fixes #90.

How did you implement it:

Split stdout by lines and try to parse the last one.

How can we verify it:

See steps to reproduce in linked issue

Todos:

• [x] Write tests
• [x] Write documentation
• [x] Fix linting errors
• [x] Provide verification config/commands/resources
• [x] Change ready for review message below

Is this ready for review?: YES