Perform ultimate cleanup of Docker Machine references in functionaal code and tests

[fabiobrz]

Issue Overview

There are yet some unused references to Docker Machine in the functional and test code and resources. Docker Machine usage is no longer supported, due to deprecation.

Expected Behaviour

Such references should be removed.

Current Behaviour

The Docker Machine integration is not used but still (partially) present.

Steps To Reproduce

1. Look for machine reference in the codebase

Additional Information

N/A