Fix docker private registry network issues
Fix docker private registry network issues

Fixes issue #24 by adding some networking settings to VirtualBox

chourobin/weave-demos,pierreozoux/guides,somespider/vm,j0rdn/coreos-rancher-vagrant,matsubo/coreos-vagrant-docker-compose,leandrocp/coreos-vagrant,chourobin/weave-demos,ianblenke/coreos-vagrant-kitchen-sink,pdxjohnny/coreos-vagrant,sjackman/coreos-vagrant,fgbreel/coreos-vagrant-kitchen-sink,kikkomep/guides,glevand/coreos--coreos-vagrant,phamviet/coreos-vagrant-es-cluster,pierreozoux/guides,monkey-H/nap-vagrant,andrewrothstein/coreos-vagrant,kikkomep/guides,lukebond/etcd-vagrant,pessoa/guides,monkey-H/nap-vagrant,errordeveloper/weave-demos,kikkomep/guides,kcyeu/coreos-vagrant,kikkomep/guides,errordeveloper/weave-demos,triple-i/coreos-vagrant,pierreozoux/guides,errordeveloper/weave-demos,ianblenke/coreos-vagrant-kitchen-sink,triple-i/coreos-vagrant,pierreozoux/guides,chourobin/weave-demos,kikkomep/guides,matsubo/coreos-vagrant-docker-compose,oveits/coreos-vagrant,pierreozoux/guides,kikkomep/guides,chourobin/weave-demos,rotespferd/coreos-vagrant,pessoa/guides,amouat/fleet-vagrant,errordeveloper/weave-demos,2yoshi/docker-test,kcyeu/coreos-vagrant,pierreozoux/guides,pierreozoux/guides,oveits/coreos-vagrant,phamviet/coreos-vagrant-es-cluster,kikkomep/guides,cornelius-keller/coreos-vagrant-tinc,quantum/coreos-vagrant,owlab-exp/coreos-vagrant-devel,kikkomep/guides,pierreozoux/guides,fgbreel/coreos-vagrant-kitchen-sink