This update for python-billiard fixes the following issues:

Update to v3.6.0.0 (boo#1136100)

+ Add support of sending parent process death signal.
+ Previous fix for handling timeouts caused a problem in warm shutdowns due to use of deepcopy.
  We now use a shallow copy of the cache and do so only when it is needed.

This update was imported from the openSUSE:Leap:15.0:Update update project.