CI/TST: suppress http debug from tests outputs
examples from https://travis-ci.org/github/pandas-dev/pandas/jobs/746072525

We have this output coming from our fixtures (we startup a http endpoint to test things), but the output is totally unecessary / distracting.

```
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /pandas-test/items.jsonl HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /pandas-test/simple_dataset.feather HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /cant_get_it/tips%231.csv HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /cant_get_it/tips.csv HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /cant_get_it/tips.csv.gz HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /cant_get_it/tips.csv.bz2 HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /cant_get_it/items.jsonl HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "PUT /cant_get_it/simple_dataset.feather HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "HEAD /pandas-test/tips.csv HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "GET /pandas-test/tips.csv HTTP/1.1" 206 -
.127.0.0.1 - - [26/Nov/2020 13:35:25] "GET /pandas-test?list-type=2&prefix=&delimiter=%2F&encoding-type=url HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "POST /pandas-test?delete HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "DELETE /pandas-test HTTP/1.1" 204 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "GET /cant_get_it?list-type=2&prefix=&delimiter=%2F&encoding-type=url HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [26/Nov/2020 13:35:25] "POST /cant_get_it?delete HTTP/1.1" 200 -
```