Fix warnings in README's example

README.md

@@ -93,14 +93,10 @@ For a more real-world example, see [example-service](example-service).
 First, let's set up the dependencies and service definition.
 
 ```rust
-
-use futures::{
-    future::{self, Ready},
-    prelude::*,
-};
+use futures::future::{self, Ready};
 use tarpc::{
     client, context,
-    server::{self, incoming::Incoming, Channel},
+    server::{self, Channel},
 };
 
 // This is the service definition. It looks a lot like a trait definition.
@@ -148,7 +144,7 @@ async fn main() -> anyhow::Result<()> {
 
     // WorldClient is generated by the #[tarpc::service] attribute. It has a constructor `new`
     // that takes a config and any Transport as input.
-    let mut client = WorldClient::new(client::Config::default(), client_transport).spawn();
+    let client = WorldClient::new(client::Config::default(), client_transport).spawn();
 
     // The client has an RPC method for each RPC defined in the annotated trait. It takes the same
     // args as defined, with the addition of a Context, which is always the first arg. The Context