anchor.diff:  # Clean up APT when done
   RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
   
  +
  
positive.code: 
  MAINTAINER Luca G. Soave <luca.soave@gmail.com>
  
  # Change REFRESHED_AT date, to force the upgrade
  ENV REFRESHED_AT 2014-15-03
  
  # Make sure the package repository is up to date
  RUN apt-get -qq update && apt-get install -y wget tar ca-certificates git
  
  # Download, compile & Install Ruby
  RUN apt-get -y install build-essential zlib1g-dev libssl-dev libreadline6-dev libyaml-dev && \
      wget http://cache.ruby-lang.org/pub/ruby/2.1/ruby-2.1.1.tar.gz && tar -xzf ruby-2.1.1.tar.gz && \
      (cd ruby-2.1.1/ && ./configure --disable-install-doc && make && make install) && rm -rf ruby-2.1.1/ && \
      rm -f /ruby-2.1.1.tar.gz
  
  # Install bundler
  RUN gem install bundler --no-rdoc --no-ri
  
negative.code: # Ruby 2.1.1 Dockerfile
  #
  # VERSION 1.0
  
  