Adding docker run as privileged otherwise systemd does not work for centos7 (and debian9 maybe)

An attempt to get systemd working in centos7 (and debian9 maybe - not tested yet).

Must run in privileged mode, and have also changed the entrypoint.sh - for now only for centos7 - following tips here: https://askubuntu.com/questions/12098/what-does-outputting-to-dev-null-accomplish-in-bash-scripts namely inside the docker container do: mkdir /run/systemd/system /usr/lib/systemd/systemd --system

Did work on my fork.