Driver: Replace xsalsa20poly1305 with crypto_secretbox (#198)

As of v0.9.1, `xsalsa20poly1305` has been deprecated. This is a mostly seamless replacement, as it appears to be the same crate authors / code / etc.

Co-authored-by: Kyle Simpson <kyleandrew.simpson@gmail.com>

src/driver/connection/error.rs

@@ -4,11 +4,11 @@ use crate::{
     driver::tasks::{error::Recipient, message::*},
     ws::Error as WsError,
 };
+use crypto_secretbox::Error as CryptoError;
 use flume::SendError;
 use serde_json::Error as JsonError;
 use std::{error::Error as StdError, fmt, io::Error as IoError};
 use tokio::time::error::Elapsed;
-use xsalsa20poly1305::aead::Error as CryptoError;
 
 /// Errors encountered while connecting to a Discord voice server over the driver.
 #[derive(Debug)]