ModuleNotFoundError: No module named 'utils'

When running main.py I get the following error:
```
$ python main.py
Traceback (most recent call last):
  File "/home/reox/git/Bonnet/src/main.py", line 16, in <module>
    from utils.early_stopping import EarlyStopping
ModuleNotFoundError: No module named 'utils'
```

I'm not sure what module that shall be. Maybe `utils.py` is missing in the repo?