travis: bump Packer version to 0.8.2
travis: bump Packer version to 0.8.2

reallyenglish/packer-templates,ody/packer-templates,sachalin/packer_centos,kaorimatz/packer-templates,sachalin/packer_centos,reallyenglish/packer-templates,wporter82/packer-templates,matsumana/packer-templates-2,ody/packer-templates,matsumana/packer-templates-2,Pluto1010/packer-templates-1,kaorimatz/packer-templates,wporter82/packer-templates,Pluto1010/packer-templates-1