anchor.diff:  
   # all changes go down here:
   # RUN ...
  -RUN apt-get install -y pylint zip
  -RUN sudo a2enmod rewrite
   
   # setup the system
   RUN echo -n "" > /etc/motd && \
  
positive.code: # Python
  RUN apt-get install -y python3 python3-dev python3-setuptools ipython3 \
      python3-scipy python3-pip python python-dev python-pip python-setuptools ipython \
      python-scipy python-matplotlib python-virtualenv virtualenvwrapper
  
  # Julia
  RUN apt-get install -y julia julia-doc
  
negative.code: # libraries and headers
  RUN apt-get install -y libcairo2-dev libjpeg62-dev libgif-dev libpq-dev \
      libboost-all-dev libzmq-dev libwww-curl-perl libbz2-dev dpkg-dev \
      ruby1.9.1-dev dialog python-gtk2 libpango1.0 libpango1.0-dev \
      libmysqlclient-dev
  
  # Deployment
  RUN wget -qO- https://toolbelt.heroku.com/install-ubuntu.sh | sh -e && \
  