fix requirements for ipython due to pycharm being bad about ipython 5.0
fix requirements for ipython due to pycharm being bad about ipython 5.0

bbc/ebu-tt-live-toolkit,bbc/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,ebu/ebu-tt-live-toolkit,bbc/ebu-tt-live-toolkit