- I unified where in file the name of `NotificationProvider.name` is placed
- I made sure that all the providers adhere to the signature of `NotificationProvider.send()`
- I made sure that all the providers use `okMsg` if returning success messages directly from the function.
Here a discussion should be had:
Should this be refactored into a constant of `NotificationProvider`? I could imagine that `NotificationProvider.SENDING_SUCCESSFULL` could be a suitable alternative.
- I made sure all providers have the URL they `POST`/`GET` to be extraced into a variable.
=> refactored this way due to Nelsons suggestion
