[COOK-2387] Pitti Postgresql PPA no longer supported, moving to PGDG apt
fix typo
Merge branch 'master' into COOK-2387
update docs
check if pgdg apt repo supports target release
Merge branch 'COOK-2387' of https://github.com/artiom/postgresql

Bring in pull request #41 on opscode-cookboos/postgresql to support
apt.postgresql.org repo