Lavalink broken in 0.16 rc

[LinuxDevon]

Capitalization in a header is illegal and causes the bot to panic. I posted in discord and figured it out shortly after. https://docs.rs/http/latest/http/header/struct.HeaderName.html#method.from_static

Panics
This function panics when the static string is a invalid header.

Until Allow panicking in constants makes its way into stable, the panic message at > compile-time is going to look cryptic, but should at least point at your header value:

Steps to reproduce:

1. checkout latest branch
2. startup a 3.X.Y lavalink server locally
3. build example lavalink-basic-bot

It would panic immediately on connect. See attached log of the panic. backtrace.log