BUG: rolling.count with axis=1 
- [ ] closes #13503 
- [X] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [X] whatsnew entry
Added axis parameter to the constructor call in the count function, fixing the original issue in #13503. This fix works for the example given in the issue. This does not fix the problem addressed by jorisvandenbossche, as that seems to be a type issue.
