Label foreign key -> self

- Removed Unused User Import
- Changed Label's Foreign Key to 'self'

```
09:19:41 (Forked_Tongue_Dev) hey, just wanted to ask why when you guys are reffering to the same model class for a foriegn key link, you don't just use self?
09:20:40 (Forked_Tongue_Dev) eg: https://github.com/wafflesfm/batter/blob/develop/batter/music/models.py #171-173
09:21:56 (Forked_Tongue_Dev) there you're using 'Label', but you could use self, which is instantly understandable and won't break if someone changes the name of the class and doesn't check the foreign key
09:23:14 (Forked_Tongue_Dev) https://docs.djangoproject.com/en/dev/ref/models/fields/#foreignkey << django docs even reccomend it
```