add inbound sms api

two endpoints:
* get all inbound sms for a service (you can limit to the X most
  recent, or filter by user's phone number [which will be normalised])
* get a summary of inbound sms for a service - returns the count of
  inbound sms in the database, and the date that the most recent was
  sent

tests/app/inbound_sms/test_rest.py

@@ -0,0 +1,93 @@
+from datetime import datetime
+
+from freezegun import freeze_time
+
+from tests.app.db import create_inbound_sms, create_service
+
+
+def test_get_inbound_sms(admin_request, sample_service):
+    one = create_inbound_sms(sample_service)
+    two = create_inbound_sms(sample_service)
+
+    json_resp = admin_request.get(
+        'inbound_sms.get_inbound_sms_for_service',
+        endpoint_kwargs={'service_id': sample_service.id}
+    )
+
+    sms = json_resp['data']
+
+    assert len(sms) == 2
+    assert {inbound['id'] for inbound in sms} == {str(one.id), str(two.id)}
+    assert sms[0]['content'] == 'Hello'
+    assert set(sms[0].keys()) == {
+        'id',
+        'created_at',
+        'service_id',
+        'notify_number',
+        'user_number',
+        'content',
+        'provider_date',
+        'provider_reference'
+    }
+
+
+def test_get_inbound_sms_limits(admin_request, sample_service):
+    with freeze_time('2017-01-01'):
+        one = create_inbound_sms(sample_service)
+    with freeze_time('2017-01-02'):
+        two = create_inbound_sms(sample_service)
+
+    sms = admin_request.get(
+        'inbound_sms.get_inbound_sms_for_service',
+        endpoint_kwargs={'service_id': sample_service.id, 'limit': 1}
+    )
+
+    assert len(sms['data']) == 1
+    assert sms['data'][0]['id'] == str(two.id)
+
+
+def test_get_inbound_sms_filters_user_number(admin_request, sample_service):
+    # user_number in the db is normalised
+    one = create_inbound_sms(sample_service, user_number='7700900001')
+    two = create_inbound_sms(sample_service, user_number='7700900002')
+
+    sms = admin_request.get(
+        'inbound_sms.get_inbound_sms_for_service',
+        endpoint_kwargs={'service_id': sample_service.id, 'user_number': '(07700) 900-001'}
+    )
+
+    assert len(sms['data']) == 1
+    assert sms['data'][0]['id'] == str(one.id)
+    assert sms['data'][0]['user_number'] == str(one.user_number)
+
+
+def test_get_inbound_sms_summary(admin_request, sample_service):
+    other_service = create_service(service_name='other_service')
+    with freeze_time('2017-01-01'):
+        create_inbound_sms(sample_service)
+    with freeze_time('2017-01-02'):
+        create_inbound_sms(sample_service)
+    with freeze_time('2017-01-03'):
+        create_inbound_sms(other_service)
+
+    summary = admin_request.get(
+        'inbound_sms.get_inbound_sms_summary_for_service',
+        endpoint_kwargs={'service_id': sample_service.id}
+    )
+
+    assert summary == {
+        'count': 2,
+        'most_recent': datetime(2017, 1, 2).isoformat()
+    }
+
+
+def test_get_inbound_sms_summary_with_no_inbound(admin_request, sample_service):
+    summary = admin_request.get(
+        'inbound_sms.get_inbound_sms_summary_for_service',
+        endpoint_kwargs={'service_id': sample_service.id}
+    )
+
+    assert summary == {
+        'count': 0,
+        'most_recent': None
+    }