Attempt to increase timeout for circleci slow tests
@LysandreJik can you help me test this?
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/2844?src=pr&el=h1) Report
> Merging [#2844](https://codecov.io/gh/huggingface/transformers/pull/2844?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/f54a5bd37f99e3933a396836cb0be0b5a497c077?src=pr&el=desc) will **not change** coverage.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/2844/graphs/tree.svg?width=650&token=9qOlN6Hb1c&height=150&src=pr)](https://codecov.io/gh/huggingface/transformers/pull/2844?src=pr&el=tree)

```diff
@@           Coverage Diff           @@
##           master    #2844   +/-   ##
=======================================
  Coverage   75.02%   75.02%           
=======================================
  Files          93       93           
  Lines       15275    15275           
=======================================
  Hits        11460    11460           
  Misses       3815     3815
```



------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/2844?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/2844?src=pr&el=footer). Last update [f54a5bd...68880a1](https://codecov.io/gh/huggingface/transformers/pull/2844?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
<|||||>Julien verbal approval :)<|||||>@sshleifer:
```
Configuration errors: 1 error occurred:

* In step 4 definition: step type "no_output_timeout" is not a valid type
```

in https://app.circleci.com/jobs/github/huggingface/transformers/18406