offloaded some apps.lyric.views responsibilities to new Celery depend fn in .tasks; core.celery created for celery config; CELERY_BROKER_URL added to .settings & throughout project; some lyric view IT responsibility now accordingly covered by task UT domain

infra/gamearray.env.j2

@@ -3,3 +3,4 @@ DJANGO_SECRET_KEY={{ secret_key.content | b64decode }}
 DJANGO_ALLOWED_HOST={{ django_allowed_host }}
 DATABASE_URL=postgresql://gamearray:{{ postgres_password }}@gamearray_postgres/gamearray
 MAILGUN_API_KEY={{ mailgun_api_key }}
+CELERY_BROKER_URL=redis://gamearray_redis:6379/0