example R code should use full URL to data file
I mislike code in examples/tutorials that cannot just be copy-pasted for reasons like calls to local data files.
read.csv now shows the example using full URL instead of the relative url.  also saves me the embarassment of failing to
knit when I'm not thoughtful about working directories ;-)
merge
Merge branch 'master' of github.com:ropensci/docs
Merge branch 'master' of github.com:ropensci/docs
Merge branch 'master' of github.com:ropensci/docs
Merge branch 'master' of github.com:ropensci/docs
try to have knitrscript read config.yml for package opts