travis failure: added debug output

[rhaschke]

This is just to understand the Travis failure of #135.
Not a real PR.

[rhaschke]

Looks like, PyYAML 5.1.1 that is used by Travis, has changed the default output format from inline:

- git: {local-name: git, uri: /tmp/tmpeB4iYa/some/uri2} 
- svn: {local-name: ros, uri: /tmp/tmpeB4iYa/some/uri1}

to expanded:

- git:
    local-name: git
    uri: /tmp/tmpuCI2fY/some/uri2
- svn:
    local-name: ros
    uri: /tmp/tmpuCI2fY/some/uri1

This make all related unittests fail on master.