Add a check that checks if redis is available on server start up

[dakaza98]

If you have forgotten to turn on redis when starting the development server, you don't get an error until you attempt to make an update on an order in ordsys. It would be a great improvement if there was a check in place that checks if redis is available when you start the server. It seems more reasonable that it would report that type of error on startup rather than on an incoming request.