anchor.diff:  RUN rm \
      openintro_1.4.tar.gz \
      assertthat_0.1.tar.gz \
  -   R6_2.1.2.tar.gz \
  +   R6_2.1.3.tar.gz \
      magrittr_1.5.tar.gz \
      lazyeval_0.2.0.tar.gz \
      DBI_0.4-1.tar.gz \
  
positive.code:    RCurl_1.95-4.8.tar.gz \
     Rcpp_0.12.6.tar.gz \
     plyr_1.8.4.tar.gz \
     R6_2.1.2.tar.gz \
     curl_1.1.tar.gz \
     openssl_0.9.4.tar.gz \
     mime_0.5.tar.gz \
     httr_1.2.1.tar.gz \
  
negative.code:    http://archive.linux.duke.edu/cran/src/contrib/tibble_1.1.tar.gz \
     http://archive.linux.duke.edu/cran/src/contrib/dplyr_0.5.0.tar.gz \
     http://archive.linux.duke.edu/cran/src/contrib/assertthat_0.1.tar.gz \
     http://archive.linux.duke.edu/cran/src/contrib/R6_2.1.3.tar.gz \
     http://archive.linux.duke.edu/cran/src/contrib/magrittr_1.5.tar.gz \
     http://archive.linux.duke.edu/cran/src/contrib/lazyeval_0.2.0.tar.gz \
     http://archive.linux.duke.edu/cran/src/contrib/DBI_0.4-1.tar.gz \
  