No pth file found for PyTorch model

Hello,

I am having issues while compiling my Pytorch model (trained on Sagemaker) with Neo. I have the following code:

```
pytorch_model = PyTorchModel(
model_data=model_data,
role=role,
sagemaker_session=sagemaker_session,
framework_version='1.2.0',
name='code-detector-model',
entry_point='sagemaker-model-entry.py',
source_dir='./',
predictor_cls=ImagePredictor,
)

pytorch_model.compile(
role=role,
target_instance_family='ml_c5',
input_shape={'data': [1, 3, 1024, 1024]},
output_path='s3://sagemaker-compiled',
job_name='compile-sagemaker-1',
framework='pytorch',
)
```

Which results in the following error:

```
UnexpectedStatusException: Error for Compilation job compile-sagemaker-1: Failed. Reason: ClientError: InputConfiguration: No pth file found for PyTorch model. Please make sure the framework you select is correct.
```

which would make you think that it can't find the model's weight file.. however, I have deployed an endpoint and successfully ran inference against the same model so that can't be the case.

Super stuck, any help would be greatly appreciated.