test_xss_scanner.py was utterly failing because of a trouble (bug?)
with the `monkeypatch` fixture failing to replace `gethostbyname`
with the correct mock function.
Indeed, when stepping through the code, the `gethostbyname` presumably
mocked was reported as a builtin python function. The problem could
then come from the fact that it is hard to monkeypatch builtin function
in python.
Using absolute imports seems to resolve the problem.
