update docker script to install 0.6
update docker script to install 0.6

vektra/packer-ubuntu12.04-cgroups,sjourdan/ubuntu-1404-k42-packer,JustinAzoff/packer-brobuntu-12.04,mitchellh/packer-ubuntu-12.04-docker,cbednarski/packer-ubuntu,JustinAzoff/packer-brobuntu-12.04,ys/packer-ubuntu-13.10-puppet