Various changes

- Update npm dependencies
- Update default fixture to exclude default celery task

src/newsreader/fixtures/default-fixture.json

@@ -1,31 +1,4 @@
 [
-{
-    "model": "django_celery_beat.periodictask",
-    "pk": 2,
-    "fields": {
-        "name": "celery.backend_cleanup",
-        "task": "celery.backend_cleanup",
-        "interval": null,
-        "crontab": 1,
-        "solar": null,
-        "clocked": null,
-        "args": "[]",
-        "kwargs": "{}",
-        "queue": null,
-        "exchange": null,
-        "routing_key": null,
-        "headers": "{}",
-        "priority": null,
-        "expires": null,
-        "one_off": false,
-        "start_time": null,
-        "enabled": true,
-        "last_run_at": "2019-11-29T04:00:00.000Z",
-        "total_run_count": 17,
-        "date_changed": "2019-11-29T04:02:15.258Z",
-        "description": ""
-    }
-},
 {
     "model": "django_celery_beat.periodictask",
     "pk": 10,