invalid value: integer 1520543558700, expected u32

[SimonTeixidor]

Hi!

Thanks for this library, it's really useful!

Today I tried to get the current playing track using sp.current_user_playing_track(). This used to work fine, but today I get:

State { next_error: Some(ErrorImpl { code: Message("invalid value: integer `1520543558700`, expected u32"), line: 2, column: 29 }), backtrace: None }

in my log. I guess spotify changed something.