[Feature] Add History of recently returned bikes

[lgehr]

It would be nice to have not only see the currently rented bikes but also a history of recent rentals.

For this we probably need to change some things as in the moment the App does not remember rented bikes.

If the user changes apps while using our app it still need to be able to getOpenRentals which were not rented with nextCompanion.
Possible solution could be to getOpenRentals if the user locks in and update every rented bike the app knows of when in MainActivity

[meierjan]

You can use rentals.json for that. It's also available in XML. It returns both running and historic-rentals.

It requires an API-key as well as a login-key.