postal code should have 7 characters

smash/web/models.py

@@ -85,7 +85,7 @@ class Subject(models.Model):
     address = models.CharField(max_length=255,
         verbose_name='Address'
     )
-    postal_code = models.CharField(max_length=6,
+    postal_code = models.CharField(max_length=7,
         verbose_name='Postal code'
     )
     city = models.CharField(max_length=50,