The manage.py included in designate-dashboard pointed to a settings file that does not exist. The tests (in tox.ini) already override these settings to use those under designatedashboard/tests/settings.py.
This patch updates manage.py to use the settings from horizon by default to reduce the confusion over which manage.py should be used to update the static files.
Change-Id: If2e0efb4240a72bedfbd09988707d4dabe9d5d1f