CLN: dont catch Exception when calling maybe_convert_numeric
and parametrized one of the tests for maybe_convert_numeric
Hello @jbrockmendel! 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 2019-09-19 00:31:58 UTC thanks @jbrockmendel 