remove names from debian box identifiers

version identifiers are sufficient, no need to add the full name. it only messes up sorting and doesn't provide much value besides that. this also aligns better with the naming convention used for ubuntu

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
fix debian box configuration in kitchen.yml

The Debian-7 box isn't available anymore. The Debian-6 box was missing a specified full version. Also added a source for both.

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
Merge pull request #20 from TelekomLabs/debian

Debian