remove the need for settings/local.py (bug 999774)

you don't need a database for webpay, there are no models that save anything

[999774] webpay $ where models.py
./src/commonware/commonware/response/cookies/models.py
./src/django-browserid/django_browserid/tests/models.py
./src/django-encrypted-cookie-session/encrypted_cookies/models.py
./src/django-session-csrf/session_csrf/models.py
./src/django-sha2/django_sha2/models.py
./webpay/base/models.py
./webpay/pin/models.py
./webpay/provider/models.py
[999774] webpay $ cat webpay/base/models.py
[999774] webpay $ cat webpay/pin/models.py
[999774] webpay $ cat webpay/provider/models.py
[999774] webpay $