add rslave for docker example, so node_exporter can receive host mount/unmount events (#660)
add rslave for docker example, so node_exporter can receive host mount/unmount events (#660)


derekmarcotte/node_exporter,siavashs/node_exporter,siavashs/node_exporter,joehandzik/node_exporter,siavashs/node_exporter,joehandzik/node_exporter,prometheus/node_exporter,joehandzik/node_exporter,derekmarcotte/node_exporter,prometheus/node_exporter,derekmarcotte/node_exporter,siavashs/node_exporter,prometheus/node_exporter,joehandzik/node_exporter,derekmarcotte/node_exporter