update everything to latest on build

Dockerfile

@@ -2,6 +2,9 @@ FROM ubuntu:16.04
 
 ADD ./sources.list /etc/apt/sources.list
 
+# normally bad form for dockerfiles, but is sandbox
+RUN DEBIAN_FRONTEND=noninteractive apt update && apt -y upgrade
+
 RUN echo "#!/bin/sh\nexit 101" > /usr/sbin/policy-rc.d
 ADD ./run.sh /tmp/run.sh
 RUN bash /tmp/run.sh && rm /tmp/run.sh