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 \
      http://archive.linux.duke.edu/cran/src/contrib/rstudioapi_0.6.tar.gz \
  -   http://archive.linux.duke.edu/cran/src/contrib/openssl_0.9.4.tar.gz \
  +   http://archive.linux.duke.edu/cran/src/contrib/openssl_0.9..tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/withr_1.0.2.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/brew_1.0-6.tar.gz \
      http://archive.linux.duke.edu/cran/src/contrib/stringi_1.1.2.tar.gz \
  
positive.code:    plyr_1.8.4.tar.gz \
     R6_2.2.0.tar.gz \
     curl_2.1.tar.gz \
     openssl_0.9.4.tar.gz \
     mime_0.5.tar.gz \
     httr_1.2.1.tar.gz \
     rstudioapi_0.6.tar.gz \
  
negative.code:    mime_0.5.tar.gz \
     httr_1.2.1.tar.gz \
     rstudioapi_0.6.tar.gz \
     openssl_0.9.5.tar.gz \
     withr_1.0.2.tar.gz \
     brew_1.0-6.tar.gz \
     stringi_1.1.2.tar.gz \
  