Security vulnerability: use safe ElementTree from defusedxml instead

[smarie]

Hi there, thanks for the great lib ! I use it in genbadge to generate a nice badge from junit reports.

However there is a known vulnerability in the stdlib XML parser: https://docs.python.org/3/library/xml.etree.elementtree.html

You should maybe try to import the ElementTree from defusedxml as recommended by the python software foundation, so that at least if people have it installed, they will be safe ?

I'll propose a PR in case you're interested