Typo in api.rs Spot::Ticker24hr

[nopbit]

Hello,

Thanks for sharing this wonderful library. I believe there is a typo in api.rs, we need to add "r" at the end of the address. It is causing 404 error.

currently:
Spot::Ticker24hr => "/api/v3/ticker/24h",

correct:
Spot::Ticker24hr => "/api/v3/ticker/24hr",

Best regards,
Mustafa