CLN: Clean csv files in test data GH34427
- [x] closes #34427
- [x] tests passed
- [ ] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

I deleted the `iris.csv` and `tips.csv` files which are unused duplicates (i.e. those in `pandas/tests/io/data/csv`). 

Thanks for the PR. Is it possible to do this the other way around? i.e. delete what's in tests/data and update the tests to make sure they point to tests/io/data/csv ? yeah agree here, let's remove the test/data ones @WillAyd & @jreback the reason why I did it that way is that a couple of files in the documentation reference the csvs in `tests/data`:
<img width="1440" alt="Screenshot 2020-05-28 at 16 27 37" src="https://user-images.githubusercontent.com/47032941/83285258-3d364580-a1de-11ea-8085-d14cd3313d24.png">

If you want to have the files in `tests/data` deleted & keep what's in `tests/io/data/csv` anyway, I can do that and change any references in the docs.  @najann yes we'd like to fix this in tests / docs.  @jreback there is also a `tips.csv` and `iris.data` file in doc/data... Should I clean that up & update any references (which exist only for `iris.data`), too? I think OK to leave the doc ones alone for now Actually made the above comment without realizing you already have to change some of the rst files; didn't realize they peered into the test folders like that

So I'm indifferent on that for now. I think this is good as is but can either fix all of the docs here or as a follow up.

I think test failure is unrelated; over to @jreback  Re-running the failing travis job: https://travis-ci.org/github/pandas-dev/pandas/builds/692962783 Travis looks ok just hasn't updated status here Thanks @najann very nice clean up and first PR @MeeseeksDev backport to 1.0.x Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 1.0.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 ef8567d0dc72ee54e21bbffe7b1c3f9ca5945909
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #34458: CLN: Clean csv files in test data GH34427'
```

4. Push to a named branch :

```
git push YOURFORK 1.0.x:auto-backport-of-pr-34458-on-1.0.x
```

5. Create a PR against branch 1.0.x, I would have named this PR:

> "Backport PR #34458 on branch 1.0.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                