Readme.md: Added verbage about running C++ and Python tests.
Readme.md: Added verbage about running C++ and Python tests.

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