add default tau=1.0 to modelgen.events.paris API
add default tau=1.0 to modelgen.events.paris API

Signed-off-by: kylemvz <85e3d43a669293812bd7569435b4d92086e60bc4@lab41.org>

d-grossman/magichour,d-grossman/magichour,d-grossman/magichour,d-grossman/magichour,d-grossman/magichour