Adding support for new Ubuntu distros: saucy (13.10) & trusty (14.04)

- Added newly supported versions of ubuntu!
- Added ubuntu-13.10 (saucy) to test-kitchen & made sure it passes!


As of 03/12/2014, saucy & trusty are supported by [PGDG Repo][1]

Note: there is no ubuntu-14.04 opscode bento box yet, so not adding it for now, but this cookbook should be future-compatible

[1]: http://apt.postgresql.org/pub/repos/apt/dists/