Cannot resolve ubuntu targets for Fuerte

Bloom uses rosdep to get a list of the default ubuntu targets, but now for Fuerte it fails with:

```
% ipython
Python 2.7.2 (default, Oct 11 2012, 20:14:37)
Type "copyright", "credits" or "license" for more information.

IPython 0.13.1 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: from rosdep2 import catkin_support

In [2]: catkin_support.get_ubuntu_targets('fuerte')
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-2-cabff3dfebd8> in <module>()
----> 1 catkin_support.get_ubuntu_targets('fuerte')

/Library/Python/2.7/site-packages/rosdep2/catkin_support.pyc in get_ubuntu_targets(rosdistro)
     57     """
     58     targets_data = get_targets()
---> 59     return targets_data[rosdistro]
     60
     61 def get_installer(installer_name):

KeyError: 'fuerte'

In [3]: catkin_support.get_ubuntu_targets('groovy')
Out[3]: ['oneiric', 'precise', 'quantal']
```

This is likely a regression from the new rosdistro stuff.