BUG: resample by BusinessHour raises ValueError
 - [x] closes #12351
 - [x] tests added / passed
 - [x] passes ``git diff upstream/master --name-only -- '*.py' | flake8 --diff``
 - [x] whatsnew entry

I've been away from this issue for a long time. Just made this PR again at PyCon 2017. Sorry for a long absence.