Suppress clippy mut_mut pedantic lint in test suite

    error: generally you want to avoid `&mut &mut _` if possible
        --> tests/test.rs:1355:13
         |
    1355 | /             futures::select! {
    1356 | |                 _ = async {
    1357 | |                     println!("{}", self.0);
    1358 | |                 }.fuse() => {}
    1359 | |             }
         | |_____________^
         |
         = note: `-D clippy::mut-mut` implied by `-D clippy::pedantic`
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#mut_mut
         = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

Author: dtolnay

tests/test.rs

@@ -1337,6 +1337,7 @@ pub mod issue158 {
 }
 
 // https://github.com/dtolnay/async-trait/issues/161
+#[allow(clippy::mut_mut)]
 pub mod issue161 {
     use async_trait::async_trait;
     use futures::future::FutureExt;