Merge branch 'tzdata_ubuntu_xenial' into 'master'

Add tzdata to Ubuntu Xenial image

See merge request !38

docker/Dockerfile_ubuntu_16.04

@@ -34,6 +34,7 @@ RUN apt-get update -q \
       ccache \
       distcc \
       unzip \
+      tzdata \
       apt-transport-https
 RUN echo "en_US.UTF-8 UTF-8" > /etc/locale.gen