add async_fn_in_trait feature for nightly

Author: liamkinne

embedded-can/src/lib.rs

@@ -2,6 +2,7 @@
 
 #![warn(missing_docs)]
 #![no_std]
+#![cfg_attr(nightly, feature(async_fn_in_trait))]
 #![allow(async_fn_in_trait)]
 
 pub mod asynch;