Feedback to Milestone 3

[Doooooris]

• preproc.R is way more simple than preproc.py. The python one is quite complicated, I understand if you want the R version to be more simple, but 15 lines of code is way to simple. Add more feature to r version, and enrich the unit test of r too.
• pip install python package failed. Try 'pip install -i https://test.pypi.org/simple/ nursepy'. Looking in indexes: https://test.pypi.org/simple/
  ERROR: Could not find a version that satisfies the requirement nursepy (from versions: none) ERROR: No matching distribution found for nursepy.