#169 Admin on teams

* adds admin column on team index view
* refactors Team model, so multiple members can become admins
* adds team migration for switch from fkey->m2m structure
* renames 'Group' to 'Permission' on user index view to avoid confusion between 'Groups' and Teams
* adds new autocomplete route for team-admin selection based on already selected members of the TeamForm

user/migrations/0004_auto_20220530_1105.py

@@ -0,0 +1,35 @@
+# Generated by Django 3.1.3 on 2022-05-30 09:05
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+def migrate_fkey_admin_to_m2m(apps, schema_editor):
+    Team = apps.get_model('user', 'Team')
+    all_teams = Team.objects.all()
+    for team in all_teams:
+        admin = team.admin
+        if admin is None:
+            continue
+        team.admins.add(admin)
+        team.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('user', '0003_team'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='team',
+            name='admins',
+            field=models.ManyToManyField(blank=True, related_name='_team_admins_+', to=settings.AUTH_USER_MODEL),
+        ),
+        migrations.RunPython(migrate_fkey_admin_to_m2m),
+        migrations.RemoveField(
+            model_name='team',
+            name='admin',
+        ),
+    ]