compare release against Ubuntu

Dockerfile

# Run with:
#
#   sudo docker build . -t latest-cliqz-release && sudo docker run --rm -it latest-cliqz-release
#
# In the end, you should see output like this:
#
# Searching for latest CLIQZ release on Ubuntu (this can take a while...)
# http://repository.cliqz.com/dist/debian-release/pool/main/c/cliqz/CLIQZ-1.13.2-release.20170508130652.x86_64.deb
# SHA256: 73f63d37c786e795ef0387095d80d2aaf10bb273916e2a262968306e3f6161cb
#
FROM ubuntu:16.04

RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 4E0C443A && \
  echo deb http://repository.cliqz.com/dist/debian-release stable main | tee /etc/apt/sources.list.d/cliqz.list

CMD echo "Searching for latest CLIQZ release on Ubuntu (this can take a while...)" && apt-get update > /dev/null 2> /dev/null && echo "http://repository.cliqz.com/dist/debian-release/$(apt-cache show cliqz | grep Filename: | sed 's/Filename: //')" && echo "SHA256: $(apt-cache show cliqz | grep SHA256: | sed 's/SHA256: //')"