Postman settings for local development

To use Postman with a local container (assuming you have it working with staging):

1. Run the local environment as described in README.md.
2. In Postman, duplicate the "development" environment, and rename the duplicate "local". (Because "development" exists on AWS; it isn't a synonym for "local".)
3. In the local environment settings, enter the same value for "notification-admin-id" as you used for staging.
4. In the local environment settings, enter "http:localhost:6011" (not httpS) for "notification-api-url".
5. In the local environment settings, enter the value of "SECRET_KEY" in the file notification-api/.env.example for "notification-client-secret".