update references to debian-7.4 to debian-8.2 in .kitchen.yml so exclusions will be effective
update references to debian-7.4 to debian-8.2 in .kitchen.yml so exclusions will be effective

sous-chefs/postgresql,patcon/postgresql,yakara-ltd/postgresql,patcon/postgresql,yakara-ltd/postgresql,Unholster/postgresql,sous-chefs/postgresql,hw-cookbooks/postgresql,Unholster/postgresql,hw-cookbooks/postgresql