add support for ubuntu 14.04

Ubuntu 14.04 includes postgresql 9.3, and no longer symlinks the ssl
certificates into the postgresql data directory, so we need to set the
certificates to the snakeoil certs in /etc
add ubuntu 1404 to kithen.yml
added 1404 to tested on docs
remove redundant certifcate config for Debian.

This was already added in #116.
Merge pull request #150 from jackpine/feature/ubuntu1404

Support for Ubuntu 14.04 (with test)