Driver, Gateway: Remove tokio 0.2 support (#118)

* Remove tokio 0.2 compat
* Remove tokio 0.2 test
* Remove tokio 0.2 CI

src/ws.rs

@@ -1,26 +1,15 @@
 use crate::model::Event;
 
 use async_trait::async_trait;
-#[cfg(not(feature = "tokio-02-marker"))]
 use async_tungstenite::{
     self as tungstenite,
     tokio::ConnectStream,
     tungstenite::{error::Error as TungsteniteError, protocol::CloseFrame, Message},
     WebSocketStream,
 };
-#[cfg(feature = "tokio-02-marker")]
-use async_tungstenite_compat::{
-    self as tungstenite,
-    tokio::ConnectStream,
-    tungstenite::{error::Error as TungsteniteError, protocol::CloseFrame, Message},
-    WebSocketStream,
-};
 use futures::{SinkExt, StreamExt, TryStreamExt};
 use serde_json::Error as JsonError;
-#[cfg(not(feature = "tokio-02-marker"))]
 use tokio::time::{timeout, Duration};
-#[cfg(feature = "tokio-02-marker")]
-use tokio_compat::time::{timeout, Duration};
 use tracing::instrument;
 
 pub type WsStream = WebSocketStream<ConnectStream>;