[cli] Upload is now compatible with folders
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=h1) Report
> Merging [#2172](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/d46147294852694d1dc701c72b9053ff2e726265?src=pr&el=desc) will **increase** coverage by `0.48%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/2172/graphs/tree.svg?width=650&token=9qOlN6Hb1c&height=150&src=pr)](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #2172      +/-   ##
==========================================
+ Coverage   80.32%   80.81%   +0.48%     
==========================================
  Files         114      113       -1     
  Lines       17102    16999     -103     
==========================================
  Hits        13737    13737              
+ Misses       3365     3262     -103
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [transformers/data/processors/squad.py](https://codecov.io/gh/huggingface/transformers/pull/2172/diff?src=pr&el=tree#diff-dHJhbnNmb3JtZXJzL2RhdGEvcHJvY2Vzc29ycy9zcXVhZC5weQ==) | `14.49% <0%> (+0.3%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=continue).
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> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=footer). Last update [d461472...fb92209](https://codecov.io/gh/huggingface/transformers/pull/2172?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
