New notification stats table

- to capture the counts of things that we do
- initial commit captures when we create an email or sms

DOES NOT know about ultimate success only that we asked our partners to ship the notification

Requires some updates when we retry sending in event of error.

tests/app/template/test_rest.py

@@ -348,7 +348,7 @@ def test_should_get_only_templates_for_that_servcie(notify_api, service_factory)
                 method='POST',
                 request_body=data
             )
-            client.post(
+            resp = client.post(
                 '/service/{}/template'.format(service_1.id),
                 headers=[('Content-Type', 'application/json'), create_auth_header],
                 data=data