Unable to run one of the domain_templates
🐛 Bug

``
Hi.
I've tried to run computer_vision_fine_tuning.py from domain_templates on Kaggle.
After first epoch(5) in the second stage, there was an error.
Error

/opt/conda/lib/python3.7/site-packages/pytorch_lightning/trainer/callback_hook.py in on_epoch_start(self)
     55         """Called when the epoch begins."""
     56         for callback in self.callbacks:
---> 57             callback.on_epoch_start(self, self.get_model())
    58
     59     def on_epoch_end(self):
/opt/conda/lib/python3.7/site-packages/pytorch_lightning/callbacks/lr_logger.py in on_epoch_start(self, trainer, pl_module)
 71
   72     def on_epoch_start(self, trainer, pl_module):
---> 73         latest_stat = self._extract_lr(trainer, 'epoch')
    74         if trainer.logger and latest_stat:
    75             trainer.logger.log_metrics(latest_stat, step=trainer.global_step)
/opt/conda/lib/python3.7/site-packages/pytorch_lightning/callbacks/lr_logger.py in _extract_lr(self, trainer, interval)
     85                     for i, pg in enumerate(param_groups):
     86                         lr, key = pg['lr'], f'{name}/pg{i + 1}'
---> 87                         self.lrs[key].append(lr)
     88                         latest_stat[key] = lr
     89                 else:
KeyError: 'learning_rate/pg1'

PyTorch Version torch-1.7.0.dev20200701+cu101 torchvision-0.8.0.dev20200701+cu101:
Pytorch-Lightning 0.8.5