some cleanup and use waitingGroups for the graceful shutdown#1

Merged

chaseisabelle merged 4 commits intochaseisabelle:masterfrom oneslash:master

May 4, 2020

Commits on May 4, 2020

some cleanup and use waitingGroups for the graceful shutdown
Sardorbek Pulatov
committed
remove listener which is not used
Sardorbek Pulatov
committed
fix deferring wg
Sardorbek Pulatov
committed
wg.Add(1) - cr fix
Sardorbek Pulatov
committed