Fix the signal command
Update the docs
Only send the stop signal to the parent
Add 'stop_children' option and fix send_signal_processes so that it sends to parent first and then all children

Previously, if a single child was already dead, the code would have given up
Allow 'stop_signal' and 'stop_children' for set command
Merge branch 'main_repo_master' into fix-signal-command
Merge branch 'refs/heads/include-wid-in-stats' into fix-signal-command
Merge branch 'main_repo_master' into fix-signal-command
Flake8 fix
Convert KeyError of send_signal_child into NoSuchProcess
Add some unit tests for the signal and shutdown code
Convert data to str for Py3
Change the default ASYNC_TEST_TIMEOUT to 10 seconds if the environment variable isn't explicitly set. Travis needs more time.
Merge pull request #603 from scottkmaxwell/fix-signal-command

Fix signal command and stopping procedure