Clean the groovy.yaml

So that it can be amended by bloom 0.3
Added a script to check the rosdistro files

Essentially the same as the check_rosdep.py, without
the check for bracketized lists.
Repair broken check scripts

They did not handle the new gbp-repos: top-level key, which
is valid yaml syntax
Added nosetest for rosdistro files

also fixed a bug in check scripts
Fix key order in rosdistro files
Merge pull request #624 from po1/clean-rosdistro

Added a script to check rosdistro files