Add config arg to create_app

Allow to easily pass config for testing

app/factory.py

@@ -36,11 +36,12 @@ def register_cli(app):
                 app.logger.debug(f'{instance} already exists')
 
 
-def create_app():
+def create_app(config=None):
     app = Flask(__name__)
 
     app.config.from_object(settings)
     app.config.from_envvar('LOCAL_SETTINGS', silent=True)
+    app.config.update(config or {})
 
     if not app.debug:
         import logging