Bug 1470243 - Use REMAP_SIGTERM=SIGQUIT with Celery on Heroku (#4747)
Bug 1470243 - Use REMAP_SIGTERM=SIGQUIT with Celery on Heroku (#4747)

As recommended by:
https://devcenter.heroku.com/articles/celery-heroku#using-remap_sigterm

For more context see:
https://github.com/celery/celery/issues/2839
edmorley/treeherder,KWierso/treeherder,KWierso/treeherder,KWierso/treeherder,edmorley/treeherder,edmorley/treeherder,KWierso/treeherder,edmorley/treeherder