add GET /service/<id>/notifications/weekly

moved format_statistics to a new service/statistics.py file, and
refactored to share code. moved tests as well, to try and enforce
separation between the restful endpoints of rest.py and the logic/
data manipulation of statistics.py

tests/app/service/test_rest.py

@@ -1,5 +1,4 @@
 import json
-import collections
 import uuid
 
 import pytest
@@ -18,9 +17,6 @@ from tests.app.conftest import (
 )
 
 
-Row = collections.namedtuple('row', ('notification_type', 'status', 'count'))
-
-
 def test_get_service_list(notify_api, service_factory):
     with notify_api.test_request_context():
         with notify_api.test_client() as client:
@@ -1125,39 +1121,3 @@ def test_get_detailed_service(notify_db, notify_db_session, notify_api, sample_s
     assert 'statistics' in service.keys()
     assert set(service['statistics'].keys()) == set(['sms', 'email'])
     assert service['statistics']['sms'] == stats
-
-
-# email_counts and sms_counts are 3-tuple of requested, delivered, failed
-@pytest.mark.idparametrize('stats, email_counts, sms_counts', {
-    'empty': ([], [0, 0, 0], [0, 0, 0]),
-    'always_increment_requested': ([
-        Row('email', 'delivered', 1),
-        Row('email', 'failed', 1)
-    ], [2, 1, 1], [0, 0, 0]),
-    'dont_mix_email_and_sms': ([
-        Row('email', 'delivered', 1),
-        Row('sms', 'delivered', 1)
-    ], [1, 1, 0], [1, 1, 0]),
-    'convert_fail_statuses_to_failed': ([
-        Row('email', 'failed', 1),
-        Row('email', 'technical-failure', 1),
-        Row('email', 'temporary-failure', 1),
-        Row('email', 'permanent-failure', 1),
-    ], [4, 0, 4], [0, 0, 0]),
-})
-def test_format_statistics(stats, email_counts, sms_counts):
-    from app.service.rest import format_statistics
-
-    ret = format_statistics(stats)
-
-    assert ret['email'] == {
-        status: count
-        for status, count
-        in zip(['requested', 'delivered', 'failed'], email_counts)
-    }
-
-    assert ret['sms'] == {
-        status: count
-        for status, count
-        in zip(['requested', 'delivered', 'failed'], sms_counts)
-    }