Added Wiki Summary Dataset
@lhoestq why my tests are not running? Maybe an issue with CircleCI, let me try to make them run The CI error `tests/test_file_utils.py::TempSeedTest::test_tensorflow` is not related to this dataset and is fixed on master, you can ignore it what I need to do now Now the delimiter of the csv reader is fixed, thanks :) 

I just added a comment suggesting to try using actual URLS instead of a manual download if possible.
This would make things more convenient for the users. Can you try using the `dl_manager` to download the train/dev/test csv files instead of requiring manual download ? Also pinging @m3hrdadfi , since I just noticed that there's already a dataset script that was created 3 weeks ago for this dataset here: https://github.com/m3hrdadfi/wiki-summary/tree/master/datasets/wiki_summary_persian @lhoestq I am getting this error while generating the dummy data
![Screenshot (181)](https://user-images.githubusercontent.com/33005287/102628819-50a40080-4170-11eb-9e96-efce74b45ff4.png)
 Can you try by adding the flag `--match_text_files "*"` ? now it worked @lhoestq pytest on dummy data passed, but on real data raising this issue
![Screenshot (196)](https://user-images.githubusercontent.com/33005287/102630784-fa848c80-4172-11eb-9f7e-e5a58dcf7abe.png)
how to resolve it
 I see ! This is because the library did some verification to make sure it downloads the same files as in the first time you ran the `datasets-cli test` command with `--save_infos`. Since we're now downloading files, the verification fails. 

To fix that you just need to regenerate the dataset_infos.json file:
```
datasets-cli test ./datasets/wiki_summary --save_infos --all_configs --ignore_verifications
``` @lhoestq I have modified everything and It worked fine, dont know why it is not passing the tests  Awesome thank you !

The CI error `tests/test_file_utils.py::TempSeedTest::test_tensorflow` is not related to your dataset and is fixed on master.
You can ignore it :)  @lhoestq anything left to do ? The dataset script is all good now ! The dummy data and the dataset_infos.json file are good too :)  @lhoestq yay, thanks for helping me out ,  merging since the CI is fixed on master @tanmoyio @lhoestq 

Thank you both!
Wiki Summary: Dataset extracted from Persian Wikipedia into the form of articles and highlights.
Link: https://github.com/m3hrdadfi/wiki-summary