Drop import_refs and add them to model_extensions

aleksis/core/migrations/0019_drop_import_refs.py

+# Generated by Django 3.0.4 on 2020-03-30 12:31
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0018_increase_length_of_group_shortname'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='group',
+            name='import_ref',
+        ),
+        migrations.RemoveField(
+            model_name='person',
+            name='import_ref',
+        ),
+    ]

aleksis/core/models.py

@@ -127,15 +127,6 @@ class Person(ExtensibleModel):
     photo = ImageCropField(verbose_name=_("Photo"), blank=True, null=True)
     photo_cropping = ImageRatioField("photo", "600x800", size_warning=True)
 
-    import_ref = models.CharField(
-        verbose_name=_("Reference ID of import source"),
-        max_length=64,
-        blank=True,
-        null=True,
-        editable=False,
-        unique=True,
-    )
-
     guardians = models.ManyToManyField(
         "self", verbose_name=_("Guardians / Parents"), symmetrical=False, related_name="children", blank=True
     )
@@ -245,15 +236,6 @@ class Group(ExtensibleModel):
         blank=True,
     )
 
-    import_ref = models.CharField(
-        verbose_name=_("Reference ID of import source"),
-        max_length=200,
-        blank=True,
-        null=True,
-        editable=False,
-        unique=True,
-    )
-
     @property
     def announcement_recipients(self):
         return list(self.members.all()) + list(self.owners.all())