Cannot add tokenizer to model repo
## Environment info
<!-- You can run the command `transformers-cli env` and copy-and-paste its output below.
     Don't forget to fill out the missing fields in that output! -->

- `transformers` version: 4.6.1
- Platform: Linux-5.4.109+-x86_64-with-Ubuntu-18.04-bionic
- Python version: 3.7.10
- Google Colab Pro Notebook

## To reproduce

Steps to reproduce the behavior:
**From Google Colab Notebook,**
1. Push model to new repo:
2. Try to add tokenizer to rep_ur using `use_auth_token`
tokenizer.push_to_hub(repo_url="https://huggingface.co/vitali/Roberta" , use_auth_token="api_****************")`

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```
CalledProcessError                        Traceback (most recent call last)
/usr/local/lib/python3.7/dist-packages/huggingface_hub/repository.py in git_push(self)
    407                 encoding="utf-8",
--> 408                 cwd=self.local_dir,
    409             )

5 frames
/usr/lib/python3.7/subprocess.py in run(input, capture_output, timeout, check, *popenargs, **kwargs)
    511             raise CalledProcessError(retcode, process.args,
--> 512                                      output=stdout, stderr=stderr)
    513     return CompletedProcess(process.args, retcode, stdout, stderr)

CalledProcessError: Command '['git', 'push']' returned non-zero exit status 1.

During handling of the above exception, another exception occurred:

OSError                                   Traceback (most recent call last)
<ipython-input-51-82c7360864ec> in <module>()
      1 # add tokenizer to repo
----> 2 tokenizer.push_to_hub(repo_url='https://huggingface.co/vitali/Roberta' , use_auth_token='api_*******')

/usr/local/lib/python3.7/dist-packages/transformers/file_utils.py in push_to_hub(self, repo_name, repo_url, commit_message, organization, private, use_auth_token)
   1891                 organization=organization,
   1892                 private=private,
-> 1893                 use_auth_token=use_auth_token,
   1894             )
   1895 

/usr/local/lib/python3.7/dist-packages/transformers/file_utils.py in _push_to_hub(cls, save_directory, save_files, repo_name, repo_url, commit_message, organization, private, use_auth_token)
   1959                 copy_tree(save_directory, tmp_dir)
   1960 
-> 1961             return repo.push_to_hub(commit_message=commit_message)

/usr/local/lib/python3.7/dist-packages/huggingface_hub/repository.py in push_to_hub(self, commit_message)
    422         self.git_add()
    423         self.git_commit(commit_message)
--> 424         return self.git_push()

/usr/local/lib/python3.7/dist-packages/huggingface_hub/repository.py in git_push(self)
    410             logger.info(result.stdout)
    411         except subprocess.CalledProcessError as exc:
--> 412             raise EnvironmentError(exc.stderr)
    413 
    414         return self.git_head_commit_url()

OSError: error: RPC failed; HTTP 403 curl 22 The requested URL returned error: 403 Forbidden
fatal: The remote end hung up unexpectedly
fatal: The remote end hung up unexpectedly
Everything up-to-date

```

## Expected behavior

Tokenizer should be added to the model repo

This is a known issue on our side. Can you try once more? cc @n1t0 @sterchelen <|||||>Same result:
```
---------------------------------------------------------------------------
CalledProcessError                        Traceback (most recent call last)
/usr/local/lib/python3.7/dist-packages/huggingface_hub/repository.py in git_push(self)
    407                 encoding="utf-8",
--> 408                 cwd=self.local_dir,
    409             )

5 frames
/usr/lib/python3.7/subprocess.py in run(input, capture_output, timeout, check, *popenargs, **kwargs)
    511             raise CalledProcessError(retcode, process.args,
--> 512                                      output=stdout, stderr=stderr)
    513     return CompletedProcess(process.args, retcode, stdout, stderr)

CalledProcessError: Command '['git', 'push']' returned non-zero exit status 1.

During handling of the above exception, another exception occurred:

OSError                                   Traceback (most recent call last)
<ipython-input-64-82c7360864ec> in <module>()
      1 # add tokenizer to repo
----> 2 tokenizer.push_to_hub(repo_url='https://huggingface.co/vitali/Roberta' , use_auth_token='api_********')

/usr/local/lib/python3.7/dist-packages/transformers/file_utils.py in push_to_hub(self, repo_name, repo_url, commit_message, organization, private, use_auth_token)
   1891                 organization=organization,
   1892                 private=private,
-> 1893                 use_auth_token=use_auth_token,
   1894             )
   1895 

/usr/local/lib/python3.7/dist-packages/transformers/file_utils.py in _push_to_hub(cls, save_directory, save_files, repo_name, repo_url, commit_message, organization, private, use_auth_token)
   1959                 copy_tree(save_directory, tmp_dir)
   1960 
-> 1961             return repo.push_to_hub(commit_message=commit_message)

/usr/local/lib/python3.7/dist-packages/huggingface_hub/repository.py in push_to_hub(self, commit_message)
    422         self.git_add()
    423         self.git_commit(commit_message)
--> 424         return self.git_push()

/usr/local/lib/python3.7/dist-packages/huggingface_hub/repository.py in git_push(self)
    410             logger.info(result.stdout)
    411         except subprocess.CalledProcessError as exc:
--> 412             raise EnvironmentError(exc.stderr)
    413 
    414         return self.git_head_commit_url()

OSError: error: RPC failed; HTTP 403 curl 22 The requested URL returned error: 403 Forbidden
fatal: The remote end hung up unexpectedly
fatal: The remote end hung up unexpectedly
Everything up-to-date

```<|||||>Hi @Kvit, I noticed many of your requests being blocked on our side, and should have fixed the problem. Can you try again?<|||||>It worked this time, thank you.