Set model admin "extra" to 0 to prevent weird behaviour and clean up the interface

src/personalisation/admin.py

@@ -5,12 +5,15 @@ from personalisation import models
 
 class TimeRuleAdminInline(admin.TabularInline):
     model = models.TimeRule
+    extra = 0
 
 class ReferralRuleAdminInline(admin.TabularInline):
     model = models.ReferralRule
+    extra = 0
 
 class VisitCountRuleAdminInline(admin.TabularInline):
     model = models.VisitCountRule
+    extra = 0
 
 class SegmentAdmin(admin.ModelAdmin):
     inlines = (TimeRuleAdminInline, ReferralRuleAdminInline, VisitCountRuleAdminInline)

src/personalisation/migrations/0011_auto_20161109_0950.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2016-11-09 08:50
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('personalisation', '0010_remove_abstractbaserule_name'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='visitcountrule',
+            name='count',
+            field=models.PositiveSmallIntegerField(default=0, null=True),
+        ),
+    ]

src/personalisation/migrations/0012_auto_20161109_0950.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2016-11-09 08:50
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('personalisation', '0011_auto_20161109_0950'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='visitcountrule',
+            name='count',
+            field=models.PositiveSmallIntegerField(null=True),
+        ),
+    ]

src/personalisation/migrations/0013_auto_20161109_0956.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.3 on 2016-11-09 08:56
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('personalisation', '0012_auto_20161109_0950'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='visitcountrule',
+            name='count',
+            field=models.PositiveSmallIntegerField(default=0, null=True),
+        ),
+    ]

src/personalisation/models.py

@@ -108,7 +108,7 @@ class VisitCountRule(AbstractBaseRule):
         ('equal_to', 'Equal to'),
     )
     operator = models.CharField(max_length=20, choices=OPERATOR_CHOICES, default="ht")
-    count = models.PositiveSmallIntegerField(default=0)
+    count = models.PositiveSmallIntegerField(default=0, null=True)
     
     def __init__(self, *args, **kwargs):
         super(VisitCountRule, self).__init__(*args, **kwargs)