introduce virtual rooms

AKOnline/admin.py

-# Register your models here.
+from django.contrib import admin
+
+from AKModel.admin import RoomAdmin
+from AKOnline.models import VirtualRoom
+
+
+@admin.register(VirtualRoom)
+class VirtualRoomAdmin(RoomAdmin):
+    model = VirtualRoom

AKOnline/migrations/0001_AKOnline.py

+# Generated by Django 3.0.6 on 2020-05-17 20:02
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    initial = True
+
+    dependencies = [
+        ('AKModel', '0033_AKOnline'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='VirtualRoom',
+            fields=[
+                ('room_ptr',
+                 models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True,
+                                      primary_key=True, serialize=False, to='AKModel.Room')),
+                ('url', models.URLField(blank=True, help_text='URL to the room or server', verbose_name='URL')),
+            ],
+            options={
+                'verbose_name': 'Virtual Room',
+                'verbose_name_plural': 'Virtual Rooms',
+            },
+            bases=('AKModel.room',),
+        ),
+    ]

AKOnline/models.py

-# Create your models here.
+from django.db import models
+from django.utils.translation import gettext_lazy as _
+
+from AKModel.models import Event, Room
+
+
+class VirtualRoom(Room):
+    """ A virtual room where an AK can be held.
+    """
+    url = models.URLField(verbose_name=_("URL"), help_text=_("URL to the room or server"), blank=True)
+
+    class Meta:
+        verbose_name = _('Virtual Room')
+        verbose_name_plural = _('Virtual Rooms')