fix(entities): add app label for entity models

Author: jarosevcik

zoo/entities/models.py

@@ -7,6 +7,9 @@
 
 
 class Group(models.Model):
+    class Meta:
+        app_label = "zoo.entities"
+
     product_owner = models.CharField(max_length=100)
     project_owner = models.CharField(max_length=100)
     maintainers = pg_fields.ArrayField(
@@ -18,6 +21,9 @@ class Group(models.Model):
 
 
 class Link(models.Model):
+    class Meta:
+        app_label = "zoo.entities"
+
     name = models.CharField(max_length=32)
     icon = models.CharField(
         max_length=16,