Add CI workflow (#23)

* Add CI workflow

* Delete interop.yml

* Delete test.yml

* deny warnings

* Fix unused mut

tonic-examples/src/routeguide/server.rs

@@ -124,7 +124,7 @@ impl server::RouteGuide for RouteGuide {
         println!("RouteChat");
 
         let stream = request.into_inner();
-        let mut state = self.state.clone();
+        let state = self.state.clone();
 
         let output = async_stream::try_stream! {
             futures::pin_mut!(stream);