anchor.diff:     stringi_1.1.5.tar.gz \
      magrittr_1.5.tar.gz \
      stringr_1.2.0.tar.gz \
  -   knitr_1.16.tar.gz \
  +   knitr_1.17.tar.gz \
      yaml_2.1.14.tar.gz \
      Rcpp_0.12.12.tar.gz \
      htmltools_0.3.6.tar.gz \
  
positive.code:    formatR_1.5.tar.gz \
     evaluate_0.10.1.tar.gz \
     markdown_0.8.tar.gz \
     knitr_1.16.tar.gz 
  
  RUN rm \
     evaluate_0.10.1.tar.gz \
  
negative.code: RUN echo  "deb http://cran.rstudio.com/bin/linux/ubuntu xenial/" >>  /etc/apt/sources.list
  RUN DEBIAN_FRONTEND=noninteractive apt-key adv --keyserver keyserver.ubuntu.com --recv-keys  E084DAB9
  
  RUN apt-get   update ; \
      apt-get   dist-upgrade -y 
  
  # we want OpenBLAS for faster linear algebra as described here: http://brettklamer.com/diversions/statistical/faster-blas-in-r/
  RUN apt-get install  -y \
  