add new key_type table

* single-column static data table that currently contains two types: 'normal' and 'team'
* key_type foreign-keyed from api_keys
  - must be not null
  - existing rows set to 'normal'
* key_type foreign-keyed from notifications
  - nullable
  - existing rows set to null
* api_key foreign-keyed from notifications
  - nullable
  - existing rows set to null

tests/__init__.py

@@ -1,7 +1,7 @@
 import uuid
 from flask import current_app
 from notifications_python_client.authentication import create_jwt_token
-from app.models import ApiKey
+from app.models import ApiKey, KEY_TYPE_NORMAL
 from app.dao.api_key_dao import (get_unsigned_secrets, save_model_api_key)
 from app.dao.services_dao import dao_fetch_service_by_id
 
@@ -14,7 +14,12 @@ def create_authorization_header(service_id=None):
             secret = secrets[0]
         else:
             service = dao_fetch_service_by_id(service_id)
-            data = {'service': service, 'name': uuid.uuid4(), 'created_by': service.created_by}
+            data = {
+                'service': service,
+                'name': uuid.uuid4(),
+                'created_by': service.created_by,
+                'key_type': KEY_TYPE_NORMAL
+            }
             api_key = ApiKey(**data)
             save_model_api_key(api_key)
             secret = get_unsigned_secrets(service_id)[0]