Add celery env var

Author: jcmc0011

backend/.env.example

@@ -10,6 +10,9 @@ FIRST_SUPERUSER=admin@example.com
 FIRST_SUPERUSER_PASSWORD=changethis
 USERS_OPEN_REGISTRATION=True
 
+# Celery
+CELERY_BROKER_URL="redis://127.0.0.1:6379/0"
+CELERY_RESULT_BACKEND="redis://127.0.0.1:6379"
 
 # Postgres
 POSTGRES_SERVER=localhost