anchor.diff:  
   # R packages we need for devtools - and we need devtools to be able to update the rmarkdown package
   RUN DEBIAN_FRONTEND=noninteractive wget \
  -   https://archive.linux.duke.edu/cran/src/contrib/rstudioapi_0.6.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/openssl_0.9.6.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/withr_1.0.2.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/brew_1.0-6.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/stringi_1.1.5.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/magrittr_1.5.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/stringr_1.2.0.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/Archive/roxygen2/roxygen2_5.0.1.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/rversions_1.0.3.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/git2r_0.18.0.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/devtools_1.13.2.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/R6_2.2.2.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/mime_0.5.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/httr_1.2.1.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/RCurl_1.95-4.8.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/Rcpp_0.12.11.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/BH_1.62.0-1.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/xml2_1.1.1.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/curl_2.6.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/jsonlite_1.5.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/digest_0.6.12.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/downloader_0.4.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/memoise_1.1.0.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/plyr_1.8.4.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/XML_3.98-1.9.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/whisker_0.3-2.tar.gz \
  -   https://archive.linux.duke.edu/cran/src/contrib/bitops_1.0-6.tar.gz
  +   https://mirrors.nics.utk.edu/cran/src/contrib/rstudioapi_0.6.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/openssl_0.9.6.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/withr_1.0.2.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/brew_1.0-6.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/stringi_1.1.5.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/magrittr_1.5.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/stringr_1.2.0.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/Archive/roxygen2/roxygen2_5.0.1.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/rversions_1.0.3.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/git2r_0.18.0.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/devtools_1.13.2.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/R6_2.2.2.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/mime_0.5.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/httr_1.2.1.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/RCurl_1.95-4.8.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/Rcpp_0.12.11.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/BH_1.62.0-1.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/xml2_1.1.1.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/curl_2.6.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/jsonlite_1.5.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/digest_0.6.12.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/downloader_0.4.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/memoise_1.1.0.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/plyr_1.8.4.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/XML_3.98-1.9.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/whisker_0.3-2.tar.gz \
  +   https://mirrors.nics.utk.edu/cran/src/contrib/bitops_1.0-6.tar.gz
   
   RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
      jsonlite_1.5.tar.gz \
  
positive.code: 
  # libraries Eric Green wanted
  RUN DEBIAN_FRONTEND=noninteractive wget \
     https://archive.linux.duke.edu/cran/src/contrib/lubridate_1.6.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/assertthat_0.2.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/lazyeval_0.2.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/rlang_0.1.1.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/tibble_1.3.3.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/ggplot2_2.2.1.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/RColorBrewer_1.1-2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/dichromat_2.0-0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/colorspace_1.3-2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/munsell_0.4.3.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/labeling_0.3.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/scales_0.4.1.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/stargazer_5.2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/reshape2_1.4.2.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/gtable_0.2.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/proto_1.0.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/minqa_1.2.4.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/nloptr_1.0.4.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/RcppEigen_0.3.3.3.0.tar.gz \
     https://archive.linux.duke.edu/cran/src/contrib/lme4_1.1-13.tar.gz
  
  RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
     lubridate_1.6.0.tar.gz  \
  
negative.code: 
  # update the R packages we will need for knitr
  RUN DEBIAN_FRONTEND=noninteractive wget \
     https://mirrors.nics.utk.edu/cran/src/contrib/knitr_1.16.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/yaml_2.1.14.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/Rcpp_0.12.11.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/htmltools_0.3.6.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/caTools_1.17.1.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/bitops_1.0-6.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/digest_0.6.12.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/stringr_1.2.0.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/markdown_0.8.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/highr_0.6.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/formatR_1.5.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/evaluate_0.10.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/mime_0.5.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/stringi_1.1.5.tar.gz \
     https://mirrors.nics.utk.edu/cran/src/contrib/magrittr_1.5.tar.gz
  
  
  RUN DEBIAN_FRONTEND=noninteractive R CMD INSTALL \
  