add/edit oauth credentials from django admin

closes #898 (closed)

arkindex/users/migrations/0014_alter_oauthcredentials_options.py

+# Generated by Django 3.2.6 on 2021-11-18 13:16
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('users', '0013_user_created_updated_fields'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='oauthcredentials',
+            options={'verbose_name': 'OAuth credentials', 'verbose_name_plural': 'OAuth credentials'},
+        ),
+    ]