Issue: ConnectionError: Couldn't reach https://raw.githubusercontent.com/huggingface/datasets/2.0.0/datasets/glue/glue.py

Hi, I meet a problem.
When I run the code:
`dataset = load_dataset('glue','sst2')`

There is a issue raising:
ConnectionError: Couldn't reach https://raw.githubusercontent.com/huggingface/datasets/2.0.0/datasets/glue/glue.py

I don't know why; it is ok when I use Google Chrome to view this url. 
Thanks for your help!

Comments:
Hi @klyuhang9,

I'm sorry but I can't reproduce your problem:
```python
In [4]: ds = load_dataset("glue", "sst2", download_mode="force_redownload")
Downloading builder script: 28.8kB [00:00, 9.15MB/s]                                                                                                                                                       
Downloading metadata: 28.7kB [00:00, 10.7MB/s]                                                                                                                                                             
Downloading and preparing dataset glue/sst2 (download: 7.09 MiB, generated: 4.78 MiB, post-processed: Unknown size, total: 11.88 MiB) to .../.cache/huggingface/datasets/glue/sst2/1.0.0/dacbe3125aa31d7f70367a07a8a9e72a5a0bfeb5fc42e75c9db75b96da6053ad...
Downloading data: 100%|███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 7.44M/7.44M [00:01<00:00, 4.12MB/s]
Dataset glue downloaded and prepared to .../.cache/huggingface/datasets/glue/sst2/1.0.0/dacbe3125aa31d7f70367a07a8a9e72a5a0bfeb5fc42e75c9db75b96da6053ad. Subsequent calls will reuse this data.  
100%|██████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 3/3 [00:00<00:00, 1047.96it/s]

In [5]: ds
Out[5]: 
DatasetDict({
    train: Dataset({
        features: ['sentence', 'label', 'idx'],
        num_rows: 67349
    })
    validation: Dataset({
        features: ['sentence', 'label', 'idx'],
        num_rows: 872
    })
    test: Dataset({
        features: ['sentence', 'label', 'idx'],
        num_rows: 1821
    })
})
```

Please, note that sometimes GitHub has some temporary connectivity issues. Feel free to retry and re-open this issue if the problem persists.

Maybe it's because we are in China.

Are you able to access the URL in your web browser?

> Are you able to access the URL in your web browser?

Yes, with or without a VPN, we (people in China) can access the URL. And we can even use wget to download these files. We can download the pretrained language model automatically with the code.
However, we CANNOT access glue.py & metric.py automatically. Every time, it will raise ConnectionError, and we have to download datasets manually (SQuAD is extremely hard to preprocess) and replace metric.py with scipy.metrics. If this problem is solved, many Chinese will save a lot of time.

> ConnectionError: Couldn't reach https://raw.githubusercontent.com/huggingface/datasets/2.0.0/datasets/glue/glue.py
> 
> I don't know why; it is ok when I use

If you would query the question `ConnectionError: Couldn't reach` in www.baidu.com (Chinese Google, Google is banned and some people cannot access it), you will find that there are so many questions about accessing `https://raw.githubusercontent.com`. There are some solutions like adding `185.199.108.133 raw.githubusercontent.com` to `C:/windows/systen32/drives/etc/hosts`, but it is time-consuming, hard for green-hand, and invalid sometimes.