BUG: FutureWarning: pandas.util.testing is deprecated. Use the functions in the public API at pandas.testing instead.   import pandas.util.testing as tm
- [x] I have checked that this issue has not already been reported.

- [x] I have confirmed this bug exists on the latest version of pandas.

- [ ] (optional) I have confirmed this bug exists on the master branch of pandas.

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**Note**: Please read [this guide](https://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports) detailing how to provide the necessary information for us to reproduce your bug.

#### Code Sample, a copy-pastable example

```python
import pandas as pd

```

#### Problem description

I'm getting this future warning when I import pandas as pd. It does not affect pandas' performance, but I think this is something that should be looked at. I have already looked into reports for similar issues, but the circumstances are different. It is also important to note that I am working in Google Colab.

#### Expected Output
There should be no warning.
#### Output of ``pd.show_versions()``

<details>

[paste the output of ``pd.show_versions()`` here leaving a blank line after the details tag]
pandas           : 1.0.3
</details>
