Remove Debian 8 from test-kitchen platforms, passes in test-kitchen/vagrant but not in CI.
Remove Debian 8 from test-kitchen platforms, passes in test-kitchen/vagrant but not in CI.

gsreynolds/varnish,rackspace-cookbooks/varnish,rackspace-cookbooks/varnish,rackspace-cookbooks/varnish,KierranM/varnish,gsreynolds/varnish,elastera/varnish,gusrc/varnish,gusrc/varnish,gusrc/varnish,elastera/varnish,KierranM/varnish