The comments above make it very clear that backwards migration is not supported but this attempts to do one anyway. Remove the code here and instead refuse to backwards migrate and warn the user. Try something like the below(also, see [this migration](https://github.com/cbmi/varify/blob/0069e45d7542b50daa1b82548d039655cf892622/varify/assessments/migrations/0002_auto__chg_field_assessment_category.py#L18) for another example:

```python

def backwards(self, orm):
    raise RuntimeError("EXPLAIN WHY MIGRATION CAN'T BE REVERSED")
```