Remove pd_array from tests
- [x] closes https://github.com/MarcoGorelli/pyladies-sprint-March-2021/issues/7
- [x] tests 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
- [ ] whatsnew entry

Thanks for looking @MarcoGorelli !

As for the changes, I understand the one for the pre-commit, but can you explain what `stdlib_array` is and where it is supposed to live? I do not see where it is defined.

When I do the change as you mention, I get this error:
`ImportError: cannot import name 'stdlib_array' from 'array'` Hey @olgarithms - sorry, I mistyped, I mean to write `from array import array as stdlib_array` (`array` is a standard library module) Thanks @olgarithms 