anchor.diff:      yum clean all
   
   # install pygments
  -RUN pip install pygments
  +RUN pip install pygments==$PYGMENTSVER
   
   # environment variables
   ENV PATH ${PATH}:$APPDIR/bin
  
positive.code:     yum clean all
  
  # install rerun
  RUN rpm -Uvh http://dl.bintray.com/rerun/rerun-rpm/rerun-1.3.4-1.el6.noarch.rpm
  
  # compile and install discount markdown library
  ENV DISCOUNTVER 2.1.8a
  ENV DISCOUNTURL http://www.pell.portland.or.us/~orc/Code/discount/discount-$DISCOUNTVER.tar.bz2
  RUN wget $DISCOUNTURL && \
      tar jxf discount-$DISCOUNTVER.tar.bz2 && \
  
negative.code: 
  FROM centos:6
  MAINTAINER Luke Heidecke <luke@solinea.com>
  
  ENV RERUNVER=1.3.4-1.el6
  ENV DISCOUNTVER=2.1.8a
  ENV PYGMENTSVER=2.0.2
  
  ENV APPDIR /app
  WORKDIR $APPDIR
  