I really don't like that this is lowercase. The release isn't labelled as "nightly". It's labelled as "Nightly". 

If there are cases where it's spelled "nIgHtLy" in the database at some point then what you should do is leave the setting as 'Nightly` and then do something like:
```
rel_release.lower() in [x.lower() for x in settings.NIGHTLY_RELEASE_TYPES]
```