Faulty unique constraint on slug field of Tag model

[gustavengstrom]

The Tag model has "unique=True" set for the slug field. This must be an error since it implies that we can only have one tag per slug... Below is the code pasted from conduit/articles/models.py.

class Tag(TimestampedModel):
tag = models.CharField(max_length=255)
slug = models.SlugField(db_index=True, unique=True)