ranker: fix default knowledge base value
Merge pull request #8 from jirikuncar/pu-ranker-config-fix

ranker: fix default knowledge base value
travis: installation process improvement

Signed-off-by: Jiri Kuncar <jiri.kuncar@gmail.com>
bulletin: fix configuration of default css path

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>