Add streaming example w/ client disconnect (#782)

examples/src/streaming/client.rs

@@ -0,0 +1,29 @@
+pub mod pb {
+    tonic::include_proto!("grpc.examples.echo");
+}
+
+use pb::{echo_client::EchoClient, EchoRequest};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut client = EchoClient::connect("http://[::1]:50051").await.unwrap();
+
+    let stream = client
+        .server_streaming_echo(EchoRequest {
+            message: "foo".into(),
+        })
+        .await
+        .unwrap();
+
+    println!("Connected...now sleeping for 2 seconds...");
+
+    tokio::time::sleep(std::time::Duration::from_secs(2)).await;
+
+    // Disconnect
+    drop(stream);
+    drop(client);
+
+    println!("Disconnected...");
+
+    Ok(())
+}