packaged version with package::devtools
moving to testthat tests, updated Layers object to a named data frame using dlply, added layers.Nature2012ftp data set
created placeholder for Scores object, to eventually populate into the datasets list like Layers
Merge pull request #8 from bbest/master

package friendly (docs, tests) with some modification to Layers, populating initial datasets layers.Nature2012ftp, and placeholder for Scores