DuplicatedKeysError: FAILURE TO GENERATE DATASET ! load_dataset('head_qa', 'en')
Hello everyone,

I try to use head_qa dataset in [https://huggingface.co/datasets/viewer/?dataset=head_qa&config=en](url)

```
!pip install datasets
from datasets import load_dataset
dataset = load_dataset(
   'head_qa', 'en')
```
When I write above load_dataset(.), it throws the following:

```
DuplicatedKeysError                       Traceback (most recent call last)

<ipython-input-6-ea87002d32f0> in <module>()
      2 from datasets import load_dataset
      3 dataset = load_dataset(
----> 4    'head_qa', 'en')

5 frames

/usr/local/lib/python3.7/dist-packages/datasets/arrow_writer.py in check_duplicate_keys(self)
    347         for hash, key in self.hkey_record:
    348             if hash in tmp_record:
--> 349                 raise DuplicatedKeysError(key)
    350             else:
    351                 tmp_record.add(hash)

DuplicatedKeysError: FAILURE TO GENERATE DATASET !
Found duplicate Key: 1
Keys should be unique and deterministic in nature
```
How can I fix the error? Thanks
