README.rst: Update the requirements list.
README.rst: Update the requirements list.

nanshe-org/rank_filter,DudLab/rank_filter,jakirkham/rank_filter,DudLab/rank_filter,nanshe-org/rank_filter,DudLab/rank_filter,jakirkham/rank_filter,nanshe-org/rank_filter,jakirkham/rank_filter