Ignore needless_lifetimes clippy lint

    warning: the following explicit lifetimes could be elided: 'a
       --> tests/test_display.rs:152:14
        |
    152 |         impl<'a> Display for Msg<'a> {
        |              ^^                  ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
        = note: `-W clippy::needless-lifetimes` implied by `-W clippy::all`
        = help: to override `-W clippy::all` add `#[allow(clippy::needless_lifetimes)]`
    help: elide the lifetimes
        |
    152 -         impl<'a> Display for Msg<'a> {
    152 +         impl Display for Msg<'_> {
        |

tests/test_display.rs

@@ -1,4 +1,8 @@
-#![allow(clippy::needless_raw_string_hashes, clippy::uninlined_format_args)]
+#![allow(
+    clippy::needless_lifetimes,
+    clippy::needless_raw_string_hashes,
+    clippy::uninlined_format_args
+)]
 
 use core::fmt::{self, Display};
 use thiserror::Error;