Without this, when running with the default pytest on Ubuntu 20.04,
it will display warnings like:
.local/lib/python3.6/site-packages/_pytest/junitxml.py:417
.local/lib/python3.6/site-packages/_pytest/junitxml.py:417: PytestDeprecationWarning: The 'junit_family' default value will change to 'xunit2' in pytest 6.0.
Add 'junit_family=xunit1' to your pytest.ini file to keep the current format in future versions of pytest and silence this warning.
Adding it here suppresses the warning.
Signed-off-by: Chris Lalancette <clalancette@openrobotics.org>
