Add bsdmainutils to Ubuntu docker

The docker image of Ubuntu 16.04 doesn't have 'colrm' utility which is
used in Perl script 'addimgid' (hostboot build tools) to construct an ID string
of hostboot image:
https://github.com/open-power/hostboot/blob/master/src/build/tools/addimgid#L39
As result, variable hbi_ImageId in hostboot is allways empty.
Installing bsdmainutils package resolves this problem.

Signed-off-by: Artem Senichev <a.senichev@yadro.com>
diff --git a/ci/Dockerfile/ubuntu1604 b/ci/Dockerfile/ubuntu1604
index 2aaa647..5c05411 100644
--- a/ci/Dockerfile/ubuntu1604
+++ b/ci/Dockerfile/ubuntu1604
@@ -7,4 +7,4 @@
   build-essential g++ git bison flex unzip \
   cpio vim-common lsb-release \
   libxml-simple-perl libxml-sax-perl libxml2-dev libxml2-utils xsltproc \
-  wget bc libssl-dev python-matplotlib python-numpy graphviz eatmydata
+  wget bc libssl-dev python-matplotlib python-numpy graphviz eatmydata bsdmainutils