Bind mounting /var/run/netns

After reading:
https://www.slideshare.net/clayton_oneill/dockerizing-the-hard-services-neutron-amp-nova

roles/neutron-controller/templates/neutron-controller.service

@@ -17,6 +17,7 @@ ExecStart=/usr/bin/docker run --name %n \
   --privileged \
   --network host \
   -v /lib/modules:/lib/modules \
+  -v /var/run/netns:/var/run/netns \
   {{ docker_image }} /etc/run.sh
 
 [Install]