changed link to prework thread for cohort 2
thinkstats v2 announce
thinkstats v2 announce
thinkstats v2 announce
thinkstats v2 announce

too many "convenient"s!
thinkstats v2 announce
Update stats.md
updated homebrew source and instructions for Yosemite
fixed typo in installation guide
removed unnecessary information from installation guide
Update README.md
Update README.md
Update README.md
Updated stats guide to reflect exercises
Updated main readme with the exercises
Underlined only-first-9-chapters of the new Think Stats in stats guide
Initial commit of exercises
Added more space to exercises guide
Updated statsmodels in installation guide
Test for statsmodels in installation guide