Can't download  'Helsinki-NLP/opus-mt-hye-eng' model
## Environment info
     
- `transformers` version: 3.0.2
- Platform: Linux-5.3.0-51-generic-x86_64-with-Ubuntu-18.04-bionic
- Python version: 3.6.9
- PyTorch version (GPU?): 1.3.1 (True)
- Tensorflow version (GPU?): not installed (NA)
- Using GPU in script?: NO
- Using distributed or parallel set-up in script?: not sure



## Information

Model I am using: MarianMTModel, AutoModelWithLMHead

The problem arises when using the official example scripts (https://huggingface.co/Helsinki-NLP/opus-mt-hye-eng):

```python 
from transformers import AutoTokenizer, AutoModelWithLMHead
tokenizer = AutoTokenizer.from_pretrained("Helsinki-NLP/opus-mt-hye-eng")
model = AutoModelWithLMHead.from_pretrained("Helsinki-NLP/opus-mt-hye-eng")
```

Gives error 

```
/home/sonja/.local/lib/python3.6/site-packages/transformers/modeling_auto.py:798: FutureWarning: The class `AutoModelWithLMHead` is deprecated and will be removed in a future version. Please use `AutoModelForCausalLM` for causal language models, `AutoModelForMaskedLM` for masked language models and `AutoModelForSeq2SeqLM` for encoder-decoder models.
  FutureWarning,
---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
~/.local/lib/python3.6/site-packages/transformers/modeling_utils.py in from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs)
    654                 if resolved_archive_file is None:
--> 655                     raise EnvironmentError
    656             except EnvironmentError:

OSError: 

During handling of the above exception, another exception occurred:

OSError                                   Traceback (most recent call last)
<ipython-input-2-04055899a280> in <module>
      1 from transformers import AutoTokenizer, AutoModelWithLMHead
      2 tokenizer = AutoTokenizer.from_pretrained("Helsinki-NLP/opus-mt-hye-eng")
----> 3 model = AutoModelWithLMHead.from_pretrained("Helsinki-NLP/opus-mt-hye-eng")

~/.local/lib/python3.6/site-packages/transformers/modeling_auto.py in from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs)
    804         for config_class, model_class in MODEL_WITH_LM_HEAD_MAPPING.items():
    805             if isinstance(config, config_class):
--> 806                 return model_class.from_pretrained(pretrained_model_name_or_path, *model_args, config=config, **kwargs)
    807         raise ValueError(
    808             "Unrecognized configuration class {} for this kind of AutoModel: {}.\n"

~/.local/lib/python3.6/site-packages/transformers/modeling_utils.py in from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs)
    660                     f"- or '{pretrained_model_name_or_path}' is the correct path to a directory containing a file named one of {WEIGHTS_NAME}, {TF2_WEIGHTS_NAME}, {TF_WEIGHTS_NAME}.\n\n"
    661                 )
--> 662                 raise EnvironmentError(msg)
    663 
    664             if resolved_archive_file == archive_file:

OSError: Can't load weights for 'Helsinki-NLP/opus-mt-hye-eng'. Make sure that:

- 'Helsinki-NLP/opus-mt-hye-eng' is a correct model identifier listed on 'https://huggingface.co/models'

- or 'Helsinki-NLP/opus-mt-hye-eng' is the correct path to a directory containing a file named one of pytorch_model.bin, tf_model.h5, model.ckpt.
```

Tried to download the model manually from link I got while debugging (https://cdn.huggingface.co/Helsinki-NLP/opus-mt-hye-eng/pytorch_model.bin) but it doesn't return anything relatable. Although for 'hye-rus' model (https://cdn.huggingface.co/Helsinki-NLP/opus-mt-hye-rus/pytorch_model.bin) I can easily download the file. Works fine for "eng-hye" and "rus-hye" too.

Hjälp, @sshleifer (sorry if mistagged)
Replicated, will fix.<|||||>use 
```python
AutoModelForSeq2SeqLM.from_pretrained('Helsinki-NLP/opus-mt-hy-en')
```

It performs better than the later hye-eng version for armenian-english.
I removed hye-eng.<|||||>Thank you! It works 