Bug: weight is not nullable

main/models.py

@@ -156,7 +156,7 @@ class Story(BaseModel):
         verbose_name_plural = "stories"
         ordering = ('closed', '-updated')
         
-    WEIGHTS = ((1, 1),(2, 2),(3, 3),(5, 5),(8, 8),(13, 13),(21, 21))
+    WEIGHTS = ((None, '------'), (1, 1),(2, 2),(3, 3),(5, 5),(8, 8),(13, 13),(21, 21))
         
     epic = models.ForeignKey(Epic, 
                              on_delete=models.PROTECT,