Add test for #32108 (error with groupby on series with period index)
- [ ] closes #32108

Hello @daxid! 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 2020-06-24 20:14:10 UTC I've done the corrections, all tests are passing now, sorry for the delay @daxid thanks for working on this. seems to have been lost in the shuffle. can you merge master to trigger ci. > @daxid thanks for working on this. seems to have been lost in the shuffle. can you merge master to trigger ci.

done can you merge master > can you merge master

done Done once again Is that version good for you ? it appears that https://github.com/pandas-dev/pandas/pull/33105#discussion_r440134823 has not been addressed period_serie -> period_series otherwise lgtm. Thanks @daxid  > it appears that [#33105 (comment)](https://github.com/pandas-dev/pandas/pull/33105#discussion_r440134823) has not been addressed period_serie -> period_series otherwise lgtm. Thanks @daxid

I am not sure to understand you request, do you want us to add a `name=` parameter  in the `period_serie` construction or do you want us to change the name `period_serie` to something else, maybe `month_serie` ? > > it appears that [#33105 (comment)](https://github.com/pandas-dev/pandas/pull/33105#discussion_r440134823) has not been addressed period_serie -> period_series otherwise lgtm. Thanks @daxid
> 
> I am not sure to understand you request, do you want us to add a `name=` parameter in the `period_serie` construction or do you want us to change the name `period_serie` to something else, maybe `month_serie` ?

Pretty sure the request is to rename `period_serie` to `period_series` > Pretty sure the request is to rename `period_serie` to `period_series`

Thanks did now saw the `s` so I wasn't understing this request, should be good now
 thanks @daxid 