ENH: Enable parsing of ISO8601-like timestamps with negative signs using pd.Timedelta (GH37172)
- [x] closes #37172 
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [x] whatsnew entry

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



There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2021-02-05 22:04:18 UTC thanks @avinashpancham 