Add Vagrant user in k3os

add-vagrant.sh

sudo adduser --disabled-password --gecos \"\" vagrant
echo vagrant:vagrant | sudo chpasswd
sudo mkdir -p /home/vagrant/.ssh
sudo chmod 0700 /home/vagrant/.ssh
sudo wget --no-check-certificate https://raw.github.com/mitchellh/vagrant/master/keys/vagrant.pub -O /home/vagrant/.ssh/authorized_keys
sudo chmod 0600 /home/vagrant/.ssh/authorized_keys
sudo chown -R vagrant /home/vagrant/.ssh
sudo echo 'vagrant  ALL=(ALL:ALL) ALL' >> /etc/sudoers
sudo mkdir -p /home/rancher/.ssh
sudo chmod 0700 /home/rancher/.ssh
sudo wget --no-check-certificate https://raw.github.com/mitchellh/vagrant/master/keys/vagrant.pub >> /home/rancher/.ssh/authorized_keys
sudo chmod 0600 /home/rancher/.ssh/authorized_keys
sudo chown -R rancher /home/rancher/.ssh