update python rnn readme; add ipython==5.0 to venv requirements (#1769)
update python rnn readme; add ipython==5.0 to venv requirements (#1769)


intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL