Issue: Got error when load cnn_dailymail dataset

When using datasets.load_dataset method to load cnn_dailymail dataset,  got error as below:

- windows os: FileNotFoundError: [WinError 3] 系统找不到指定的路径。: 'D:\\SourceCode\\DataScience\\HuggingFace\\Data\\downloads\\1bc05d24fa6dda2468e83a73cf6dc207226e01e3c48a507ea716dc0421da583b\\cnn\\stories'
- google colab: NotADirectoryError: [Errno 20] Not a directory: '/root/.cache/huggingface/datasets/downloads/1bc05d24fa6dda2468e83a73cf6dc207226e01e3c48a507ea716dc0421da583b/cnn/stories'

The code is to load dataset:
windows os:
```
from datasets import load_dataset

dataset = load_dataset("cnn_dailymail", "3.0.0", cache_dir="D:\\SourceCode\\DataScience\\HuggingFace\\Data")

```
google colab:
```
import datasets

train_data = datasets.load_dataset("cnn_dailymail", "3.0.0", split="train")
```

Comments:
Was able to reproduce the issue on Colab; full logs below. 

```
---------------------------------------------------------------------------
NotADirectoryError                        Traceback (most recent call last)
[<ipython-input-2-39967739ba7f>](https://localhost:8080/#) in <module>()
      1 import datasets
      2 
----> 3 train_data = datasets.load_dataset("cnn_dailymail", "3.0.0", split="train")

5 frames
[/usr/local/lib/python3.7/dist-packages/datasets/load.py](https://localhost:8080/#) in load_dataset(path, name, data_dir, data_files, split, cache_dir, features, download_config, download_mode, ignore_verifications, keep_in_memory, save_infos, revision, use_auth_token, task, streaming, script_version, **config_kwargs)
   1705         ignore_verifications=ignore_verifications,
   1706         try_from_hf_gcs=try_from_hf_gcs,
-> 1707         use_auth_token=use_auth_token,
   1708     )
   1709 

[/usr/local/lib/python3.7/dist-packages/datasets/builder.py](https://localhost:8080/#) in download_and_prepare(self, download_config, download_mode, ignore_verifications, try_from_hf_gcs, dl_manager, base_path, use_auth_token, **download_and_prepare_kwargs)
    593                     if not downloaded_from_gcs:
    594                         self._download_and_prepare(
--> 595                             dl_manager=dl_manager, verify_infos=verify_infos, **download_and_prepare_kwargs
    596                         )
    597                     # Sync info

[/usr/local/lib/python3.7/dist-packages/datasets/builder.py](https://localhost:8080/#) in _download_and_prepare(self, dl_manager, verify_infos, **prepare_split_kwargs)
    659         split_dict = SplitDict(dataset_name=self.name)
    660         split_generators_kwargs = self._make_split_generators_kwargs(prepare_split_kwargs)
--> 661         split_generators = self._split_generators(dl_manager, **split_generators_kwargs)
    662 
    663         # Checksums verification

[/root/.cache/huggingface/modules/datasets_modules/datasets/cnn_dailymail/3cb851bf7cf5826e45d49db2863f627cba583cbc32342df7349dfe6c38060234/cnn_dailymail.py](https://localhost:8080/#) in _split_generators(self, dl_manager)
    253     def _split_generators(self, dl_manager):
    254         dl_paths = dl_manager.download_and_extract(_DL_URLS)
--> 255         train_files = _subset_filenames(dl_paths, datasets.Split.TRAIN)
    256         # Generate shared vocabulary
    257 

[/root/.cache/huggingface/modules/datasets_modules/datasets/cnn_dailymail/3cb851bf7cf5826e45d49db2863f627cba583cbc32342df7349dfe6c38060234/cnn_dailymail.py](https://localhost:8080/#) in _subset_filenames(dl_paths, split)
    154     else:
    155         logger.fatal("Unsupported split: %s", split)
--> 156     cnn = _find_files(dl_paths, "cnn", urls)
    157     dm = _find_files(dl_paths, "dm", urls)
    158     return cnn + dm

[/root/.cache/huggingface/modules/datasets_modules/datasets/cnn_dailymail/3cb851bf7cf5826e45d49db2863f627cba583cbc32342df7349dfe6c38060234/cnn_dailymail.py](https://localhost:8080/#) in _find_files(dl_paths, publisher, url_dict)
    133     else:
    134         logger.fatal("Unsupported publisher: %s", publisher)
--> 135     files = sorted(os.listdir(top_dir))
    136 
    137     ret_files = []

NotADirectoryError: [Errno 20] Not a directory: '/root/.cache/huggingface/datasets/downloads/1bc05d24fa6dda2468e83a73cf6dc207226e01e3c48a507ea716dc0421da583b/cnn/stories'
```

Hi @jon-tow, thanks for reporting. And hi @dynamicwebpaige, thanks for your investigation. 

This issue was already reported 
- #3784

and its root cause is a change in the Google Drive service. See:
- #3786 

We have already fixed it. See:
- #3787 

We are planning to make a patch release today (indeed, we were planning to do it last Friday).

In the meantime, you can get this fix by installing our library from the GitHub master branch:
```shell
pip install git+https://github.com/huggingface/datasets#egg=datasets
```
Then, if you had previously tried to load the data and got the checksum error, you should force the redownload of the data (before the fix, you just downloaded and cached the virus scan warning page, instead of the data file):
```shell
load_dataset("...", download_mode="force_redownload")
```

CC: @lhoestq