Upgrade to celery 5.0 (#421)

Mariatta · web-flow · commit e71602d347fb · 2020-12-12T16:49:19.000-08:00
The command line invocation for celery was changed in v5.
diff --git a/Procfile b/Procfile
@@ -1,2 +1,2 @@
 web: python3 -m miss_islington
-worker: celery worker --app=miss_islington.tasks.app --concurrency=1
+worker: celery --app miss_islington.tasks.app worker --concurrency=1

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`	`1`	`web: python3 -m miss_islington`
`2`		`-worker: celery worker --app=miss_islington.tasks.app --concurrency=1`
	`2`	`+worker: celery --app miss_islington.tasks.app worker --concurrency=1`