Now that we've moved all our repos from kiln to github, no longer query kiln.

Summary:
This will make this script more reliable since there's one less API
call that can fail.

Once this is in, I will visit the following urls to deactivate each of
these kiln repositories (since they're no longer ever being updated).

    http://phabricator.khanacademy.org/diffusion/GMAA/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GMAHT/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GMAI/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GMAIE/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GMAIO/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPA/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPBAA/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPOT/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPPT/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPRS/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPRT/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GW/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GSS/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GAS/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GCBC/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GCK/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GCL/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTAS/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTHS/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTLT/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTMU/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTNDR/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTPB/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTRM/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTS/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTOSK/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTSI/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTTC/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GTYE/edit/activate/
    http://phabricator.khanacademy.org/diffusion/GPW/edit/activate/

Test Plan:
Ran
   ./update_phabricator_repositories.py -n /tmp
and saw it say:

   Repository ssh://khanacademy.kilnhg.com/Website/tools/scripts has been deleted: run (on toby):
      env PHABRICATOR_ENV=khan ~/internal-webserver/phabricator/bin/remove destroy rGTS

and likewise for all the other kiln repositories, but nothing else.
(Once I deactivate all these repos, these warning messages will stop.)

Reviewers: alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D13489