Add a new table to store the api information for a service inbound sms message.

Including:
 - url to push the inbound sms to
 - bearer_token to be added to the header of the request.

The services will be expected to manage these properties.

tests/app/dao/test_save_service_inbound_api.py

@@ -0,0 +1,20 @@
+from app.dao.service_inbound_api_dao import save_service_inbound_api
+from app.models import ServiceInboundApi
+
+
+def test_save_service_inbound_api(sample_service):
+    service_inbound_api = ServiceInboundApi(
+        service_id=sample_service.id,
+        url="https::/some_service/inbound_messages",
+        bearer_token="some_unique_string"
+    )
+
+    save_service_inbound_api(service_inbound_api)
+
+    results = ServiceInboundApi.query.all()
+    assert len(results) == 1
+    assert results[0].id
+    assert results[0].service_id == sample_service.id
+    assert results[0].url == "https::/some_service/inbound_messages"
+    assert results[0].unsigned_bearer_token == "some_unique_string"
+    assert results[0].bearer_token != "some_unique_string"