CircleCI stores cleaner output at test_outputs.txt
Author: sshleifer
Pull request: yes

Changes:

- Don't run pytest with `-v` or `--cov`. I left run_tests_torch_and_tf using `--cov` but would love to delete that. I have never used circleci to determine code coverage.

- the run* jobs create artifact files called test_output.txt that are easier to read than scrolling in the circleci gui

- self scheduled runner also attempts to make a test_output.txt

Before:
![image](https://user-images.githubusercontent.com/6045025/85790787-d33a8e80-b6fe-11ea-9e10-d4c48dfe713f.png)


After:

[artifact](https://53278-155220641-gh.circle-artifacts.com/0/test_output.txt) is very manageable

and [ui](https://app.circleci.com/pipelines/github/huggingface/transformers/8144/workflows/816b1f60-bda9-4456-9f51-92d6cff7b266/jobs/53278/steps) is less noisy.



Comments:
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/5291?src=pr&el=h1) Report
> Merging [#5291](https://codecov.io/gh/huggingface/transformers/pull/5291?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/79a82cc06aaa68088639bf9bb000752cfd33a8c6&el=desc) will **decrease** coverage by `1.39%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/5291/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/5291?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #5291      +/-   ##
==========================================
- Coverage   79.29%   77.90%   -1.40%     
==========================================
  Files         138      138              
  Lines       24282    24282              
==========================================
- Hits        19254    18916     -338     
- Misses       5028     5366     +338     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/5291?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_tf\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/5291/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9vcGVuYWkucHk=) | `20.78% <0.00%> (-74.20%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_distilbert.py](https://codecov.io/gh/huggingface/transformers/pull/5291/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9kaXN0aWxiZXJ0LnB5) | `66.25% <0.00%> (-32.52%)` | :arrow_down: |
| [src/transformers/trainer.py](https://codecov.io/gh/huggingface/transformers/pull/5291/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy90cmFpbmVyLnB5) | `39.38% <0.00%> (-0.24%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5291/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `87.48% <0.00%> (-0.15%)` | :arrow_down: |
| [src/transformers/file\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5291/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9maWxlX3V0aWxzLnB5) | `79.59% <0.00%> (+0.33%)` | :arrow_up: |
| [src/transformers/modeling\_tf\_pytorch\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5291/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9weXRvcmNoX3V0aWxzLnB5) | `89.30% <0.00%> (+1.25%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/5291?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/5291?src=pr&el=footer). Last update [79a82cc...73e5da8](https://codecov.io/gh/huggingface/transformers/pull/5291?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).


I wonder how it looks when it fails. Is it the same output you would usually see? If  that's the case, I'm all for that change!

Yes the tracebacks are completely unchanged. You just only see a `.` if the tests passes. And you don't have to scroll through `logger.info` (if you don't want to, it's still in the default circleci page).

Merging. Tag me if any issues.