Corrects the second R subset instruction on slide 16

Corrects the second R subset instruction on slide 16 and the erroneous
output (the observation heights=192.3) by recompiling the slides.
Merge pull request #7 from ajalexander/master

Adding missing library call in README
Merge pull request #5 from jpoliv/master

representingDataR: slide 16: second subset example: wrong instruction and output
Merge branch 'master', remote-tracking branch 'upstream/master'
Organized lectures by week, added week2 lectures, created folder for pdfs
 * Getting Data (Part 2): slide 4 title correction (s/relative/absolute/)
Update week2/002structureOfADataAnalysis2/index.html

charcters -> characters
Merge pull request #10 from schuess/patch-1

Update week2/002structureOfADataAnalysis2/index.html
Merge pull request #9 from jpoliv/master

Getting Data (Part 2): slide 4 title correction
Merge branch 'master', remote-tracking branch 'upstream/master'