update Country model

apps/location/migrations/0005_auto_20190822_1144.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.4 on 2019-08-22 11:44
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('location', '0004_auto_20190822_0710'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='country',
+            name='code',
+            field=models.CharField(max_length=255, unique=True, verbose_name='Code'),
+        ),
+    ]

apps/location/models.py

@@ -14,8 +14,7 @@ class Country(ProjectBaseMixin):
 
     name = JSONField(null=True, blank=True, default=None,
                      verbose_name=_('Name'), help_text='{"en":"some text"}')
-    code = models.CharField(max_length=255, blank=True, null=True,
+    code = models.CharField(max_length=255, unique=True, verbose_name=_('Code'))
-                            default=None, unique=True, verbose_name=_('Code'))
 
     objects = CountryManager()