Trying to get the test environment working

Author: jgaa

Diff for: ci/jenkins/Dockefile.ubuntu-xenial

@@ -11,7 +11,6 @@ RUN apt-get -q update &&\
     automake autoconf build-essential \
     zlib1g-dev g++ cmake make libboost-all-dev libssl-dev \
     openjdk-8-jdk &&\
-    gem install --no-ri --no-rdoc fpm &&\
     apt-get -y -q autoremove &&\
     apt-get -y -q clean