allow BLE001 if traceback is generated?

`BLE001` allows
```python
try:
        foo
except Exception:
        raise
```
but disallows:
```python
try:
        foo
except Exception:
        print(traceback.format_exc())
        logger.log(traceback.format_exc())
        logger.exception('something is broken')
```

I think generating a traceback is an indication of handling the exception properly.