BUG fixed broken link GH16279
GH16279

http://nbviewer.jupyter.org/github/pandas-dev/pandas/blob/master/doc/source/html-styling.ipynb gives 404, changed to
http://nbviewer.ipython.org/github/pandas-dev/pandas/blob/master/doc/source/style.ipynb

 - [ ] closes GH16279
 - [ ] tests added / passed
 - [ ] passes ``git diff upstream/master --name-only -- '*.py' | flake8 --diff``
 - [ ] whatsnew entry
