Update testing.py
Comment added
Hello @spchandgude! Thanks for opening this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:

* In the file [`pandas/testing.py`](https://github.com/pandas-dev/pandas/blob/c5b3b183b4a8880539ef752097289ae7c373ce69/pandas/testing.py):

> [Line 4:1](https://github.com/pandas-dev/pandas/blob/c5b3b183b4a8880539ef752097289ae7c373ce69/pandas/testing.py#L4): [E265](https://duckduckgo.com/?q=pep8%20E265) block comment should start with '# '

 Thanks for your interest in contributing.

I don't think this comment adds much value to this file in particular. If you're interest in contributing, we recommend looking at the issues labeled `good first issue`: https://github.com/pandas-dev/pandas/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22