Merge branch 'master' of github.com:DataScienceSpecialization/courses

* 'master' of github.com:DataScienceSpecialization/courses:
  Added some shiny stuff
  Fix graphs in colors lecture
  Re-export PDF slides
  Re-export PDF slides
  Copy with new name
  Re-export PDF slides
  update
  Added a second shiny lecture
  Added a second shiny lecture and some example apps
  Small changes to the slidify lecture
  Finished rCharts and added rgl and rMaps
  some image files in regression
  Added rstudio lecture and some images
  Some small edits
  Deleted a pdf file
  fixed date
Merge branch 'master' of github.com:DataScienceSpecialization/courses

* 'master' of github.com:DataScienceSpecialization/courses:
  added pdfs for brian in statinf
  Added some lecture files
  Added a bunch of pdfs
  Added some figures
  Fixed some errors
  recompiled 03_04
  Minor corrections to intro page
  Added a hw2
  Added hw2
  Worked on hw2
  Set correct answer for question 2
  Added a hw 2
  Fixed a small error
  Added HW files
  Added some homework
  update
Merge branch 'master' of github.com:rdpeng/courses

* 'master' of github.com:rdpeng/courses:
  Some new PDFs
  Rename pdf slides
  Update PDF/PNG slides
  Zip file of data used in lecture
  updates/modifications to yhat example
  Evaluate date/time code
  Fix coding for dates
  Change the expoent of Xip
  Change Title fo article
  Rename pdf slides
  Update PDF/PNG slides
  Zip file of data used in lecture
  updates/modifications to yhat example
  Evaluate date/time code
  Fix coding for dates
Merge branch 'master' of github.com:DataScienceSpecialization/courses

* 'master' of github.com:DataScienceSpecialization/courses:
Merge pull request #72 from rdpeng/master

just update this yo