[devtools] don't hide warnings and errors during tests
The markdown module in jessie turns all warnings into logging calls, so
this allows me to still see deprecation warnings when running tests.
usr/lib/PY_VERSION/*-packages/cubicweb/entities/
usr/lib/PY_VERSION/*-packages/cubicweb/ext/
usr/share/cubicweb/cubes/
usr/lib/PY_VERSION/*-packages/cubicweb/*.py