I write here to document my trials and errors how to run this template in case someone else run to this problem
After changing my_module/metadata.py as suggested and running internal/generate.py, to my surprise both <my_named_module>/main.py and tests/test_main.py complained, that they can not find <my_named_module> (note, "paver test_all" worked).
The solution was to add path/to/project to PYTHONPATH