Add script to diff installed R packages
Add script to diff installed R packages

Used to check if all the R packages in the current
R hub image are present in the new R hub image.

ryanlovett/datahub,berkeley-dsep-infra/datahub,ryanlovett/datahub,berkeley-dsep-infra/datahub,berkeley-dsep-infra/datahub,ryanlovett/datahub