Gotify version API endpoint compatibility

[megatwig]

Multiscrobbler calls the /version endpoint for Gotify servers (here) to check server health when initializing. This endpoint doesn't exist in Pushbits so isn't compatible.

Could this endpoint be added for compatibility? It would be a good place to offer up some indication that this is Gotify-compatible and not true Gotify too, in case sending applications want to check for feature support.