fix for pyTorch 1.1

[Borda]

What does this PR do?

Follow-up to #546 and #549 Fixes #491

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

[Borda]

now the error is following but it seems not to be related to this module...

>       checkpoint = init_checkpoint_callback(logger)
tests/test_a_restore_models.py:82: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
tests/utils.py:235: in init_checkpoint_callback
    exp = logger.experiment
pytorch_lightning/logging/test_tube_logger.py:37: in experiment
    rank=self.rank,
.tox/py37/lib/python3.7/site-packages/test_tube/log.py:154: in __init__
    super().__init__(log_dir=log_dir, *args, **kwargs)
.tox/py37/lib/python3.7/site-packages/torch/utils/tensorboard/writer.py:199: in __init__
    self._get_file_writer()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <test_tube.log.Experiment object at 0x7f533d7c8b70>
[1m    def _get_file_writer(self):
        """Returns the default FileWriter instance. Recreates it if closed."""
        if self.rank > 0:
            return TTDummyFileWriter()
    
        if self.all_writers is None or self.file_writer is None:
>           if self.purge_step is not None:
E           AttributeError: 'Experiment' object has no attribute 'purge_step'
.tox/py37/lib/python3.7/site-packages/test_tube/log.py:504: AttributeError

[williamFalcon]

@Borda that’s a test tube error. maybe submit a quick PR there?

[Borda]

well, I was confused because test-tube does not have PyTorch in requirements

[williamFalcon]

true. but test-tube is a subclass of summarywriter

[Borda]

@jeffling @neggert @Ir1d anyone wants to make a fix on test-tube? :)

[Borda]

@williamFalcon it seems that the fix helps for crashing, could you merge and release a new version 0.7.4? Then I would finalize this PR... :)

https://circleci.com/workflow-run/e15c02ed-128b-4081-b283-ea6e2690fdb4

[williamFalcon]

@Borda 0.7.4 pushed!

[williamFalcon]

@Borda looks like test-tube install has a bug.

never mind, fixed it.