ASSIN2 dataset checksum bug
Using latest code, I am still facing the issue.

```python
(base) vimos@vimosmu ➜  ~ ipython
Python 3.6.7 | packaged by conda-forge | (default, Nov  6 2019, 16:19:42) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.11.1 -- An enhanced Interactive Python. Type '?' for help.

In [1]: from datasets import load_dataset

In [2]: load_dataset("assin2")
Downloading builder script: 4.24kB [00:00, 244kB/s]
Downloading metadata: 2.58kB [00:00, 2.19MB/s]
Using custom data configuration default
Downloading and preparing dataset assin2/default (download: 2.02 MiB, generated: 1.21 MiB, post-processed: Unknown size, total: 3.23 MiB) to /home/vimos/.cache/huggingface/datasets/assin2/default/1.0.0/8467f7acbda82f62ab960ca869dc1e96350e0e103a1ef7eaa43bbee530b80061...
Downloading data: 1.51MB [00:00, 102MB/s]
Downloading data: 116kB [00:00, 63.6MB/s]
Downloading data: 493kB [00:00, 95.8MB/s]                                                            
Downloading data files: 100%|██████████████████████████████████████████| 3/3 [00:00<00:00,  8.27it/s]
---------------------------------------------------------------------------
ExpectedMoreDownloadedFiles               Traceback (most recent call last)
<ipython-input-2-b367d1ffd68e> in <module>
----> 1 load_dataset("assin2")

~/anaconda3/lib/python3.6/site-packages/datasets/load.py 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, **config_kwargs)
   1694         ignore_verifications=ignore_verifications,
   1695         try_from_hf_gcs=try_from_hf_gcs,
-> 1696         use_auth_token=use_auth_token,
   1697     )
   1698

~/anaconda3/lib/python3.6/site-packages/datasets/builder.py 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)
    604                     if not downloaded_from_gcs:
    605                         self._download_and_prepare(
--> 606                             dl_manager=dl_manager, verify_infos=verify_infos, **download_and_prepare_kwargs
    607                         )
    608                     # Sync info

~/anaconda3/lib/python3.6/site-packages/datasets/builder.py in _download_and_prepare(self, dl_manager, verify_infos)
   1102
   1103     def _download_and_prepare(self, dl_manager, verify_infos):
-> 1104         super()._download_and_prepare(dl_manager, verify_infos, check_duplicate_keys=verify_infos)
   1105
   1106     def _get_examples_iterable_for_split(self, split_generator: SplitGenerator) -> ExamplesIterable:

~/anaconda3/lib/python3.6/site-packages/datasets/builder.py in _download_and_prepare(self, dl_manager, verify_infos, **prepare_split_kwargs)
    675         if verify_infos:
    676             verify_checksums(
--> 677                 self.info.download_checksums, dl_manager.get_recorded_sizes_checksums(), "dataset source files"
    678             )
    679

~/anaconda3/lib/python3.6/site-packages/datasets/utils/info_utils.py in verify_checksums(expected_checksums, recorded_checksums, verification_name)
     31         return
     32     if len(set(expected_checksums) - set(recorded_checksums)) > 0:
---> 33         raise ExpectedMoreDownloadedFiles(str(set(expected_checksums) - set(recorded_checksums)))
     34     if len(set(recorded_checksums) - set(expected_checksums)) > 0:
     35         raise UnexpectedDownloadedFile(str(set(recorded_checksums) - set(expected_checksums)))

ExpectedMoreDownloadedFiles: {'https://drive.google.com/u/0/uc?id=1kb7xq6Mb3eaqe9cOAo70BaG9ypwkIqEU&export=download', 'https://drive.google.com/u/0/uc?id=1J3FpQaHxpM-FDfBUyooh-sZF-B-bM_lU&export=download', 'https://drive.google.com/u/0/uc?id=1Q9j1a83CuKzsHCGaNulSkNxBm7Dkn7Ln&export=download'}
``` That's true. Steps to reproduce the bug on Google Colab:

```
git clone https://github.com/huggingface/datasets.git
cd datasets
pip install -e .
python -c "from datasets import load_dataset; print(load_dataset('assin2')['train'][0])"
```

However the dataset will load without any problems if you just install version 2.0.0:

 ```
pip install datasets
python -c "from datasets import load_dataset; print(load_dataset('assin2')['train'][0])"
```

Any thoughts @lhoestq ? Right indeed ! Let me open a PR to fix this.
The dataset_infos.json file that stores some metadata about the dataset to download (and is used to verify it was correctly downloaded) hasn't been updated correctly Not sure what the status of this is, but personally I am still getting this error, with glue. Can you open a new issue if you got an error with glue please ? Have posted at #4241
## Describe the bug

Checksum error after trying to load the [ASSIN 2 dataset](https://huggingface.co/datasets/assin2).

`NonMatchingChecksumError` triggered by calling `load_dataset("assin2")`.

Similar to #3952 , #3942 , #3941 , etc.

```
---------------------------------------------------------------------------
NonMatchingChecksumError                  Traceback (most recent call last)
[<ipython-input-13-c664a92ad5e7>](https://localhost:8080/#) in <module>()
----> 1 load_dataset('assin2')

4 frames
[/usr/local/lib/python3.7/dist-packages/datasets/utils/info_utils.py](https://localhost:8080/#) in verify_checksums(expected_checksums, recorded_checksums, verification_name)
     38     if len(bad_urls) > 0:
     39         error_msg = "Checksums didn't match" + for_verification_name + ":\n"
---> 40         raise NonMatchingChecksumError(error_msg + str(bad_urls))
     41     logger.info("All the checksums matched successfully" + for_verification_name)
     42 

NonMatchingChecksumError: Checksums didn't match for dataset source files:
['https://drive.google.com/u/0/uc?id=1Q9j1a83CuKzsHCGaNulSkNxBm7Dkn7Ln&export=download']
```

## Steps to reproduce the bug
```python
from datasets import load_dataset
load_dataset("assin2")
```

## Expected results
Load the dataset.

## Actual results
The dataset won't load. 

## Environment info
- `datasets` version: 2.0.1.dev0
- Platform: Google Colab
- Python version:  3.7.12
- PyArrow version: 6.0.1
