anchor.diff:  	apt-get install curl
   
   # Install PHP Composer.
  -RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
  -RUN composer --version
  +RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer && \
  +	composer --version
   
   # Install PHP Composer dependecies.
   #
  
positive.code: 	apt-get install -y --force-yes firefox
  
  # Adjust Firefox installation directory.
  RUN sudo chmod -R +x /opt/firefox/
  
  # Install Firefox dependencies.
  #
  
negative.code: #	- libgtk-3-0
  #	- libgtk2.0-0-dbg
  RUN apt-get update && \
  	apt-get install -y libdbus-glib-1-2 && \
  	apt-get install -y libxrender-dev && \
  	apt-get install -y libxcomposite-dev && \
  	apt-get install -y libasound-dev && \
  	apt-get install -y libgtk-3-0 && \
  	apt-get install -y libgtk2.0-0-dbg
  
  # Download Selenium standalone server (2.49.1).
  RUN wget -O selenium-server-standalone-2.49.1.jar http://goo.gl/rQhaxb -P /opt/
  
  # Install PHP 5.
  #
  