switch apt source to xenial
switch apt source to xenial

Signed-off-by: Corey Hemminger <3d5830a0257e340f5a259a86df2f7fb1445ca1c1@hotmail.com>

gshively11/jenkins,opscode-cookbooks/jenkins,chef-cookbooks/jenkins,gshively11/jenkins,chef-cookbooks/jenkins,opscode-cookbooks/jenkins,gshively11/jenkins,chef-cookbooks/jenkins,opscode-cookbooks/jenkins