Merge pull request #1 from bcaffo/gh-pages

merging
R packages lecture
Classes and methods lecture
Rename Rmd file
Add html and md files
Figures
Edits; remove cache mean example
Add figure/
Examples
bold
Tweaks and edits
Example R package
Update week 4 announcement
Merge branch 'master' of github.com:rdpeng/courses

* 'master' of github.com:rdpeng/courses:
  Prog Assgn 2 is a peer assessment
Merge branch 'dataprod'

* dataprod:
  Example R package
  Tweaks and edits
  bold
  Examples
  Add figure/
  Edits; remove cache mean example
  Figures
  Add html and md files
  Rename Rmd file
  Classes and methods lecture
  R packages lecture
Merge pull request #15 from rdpeng/master

Classes & Methods / R Packages for Data Products
Update
Talk about DSS sequence
Makefile for creating PDF slides
Merge branch 'master' of github.com:DataScienceSpecialization/courses

* 'master' of github.com:DataScienceSpecialization/courses: