Ignore needless_lifetimes clippy lint

    warning: the following explicit lifetimes could be elided: 'a
      --> src/rcvec.rs:96:6
       |
    96 | impl<'a, T> RcVecMut<'a, T> {
       |      ^^              ^^
       |
       = 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
       |
    96 - impl<'a, T> RcVecMut<'a, T> {
    96 + impl<T> RcVecMut<'_, T> {
       |

src/lib.rs

@@ -105,6 +105,7 @@
     clippy::missing_safety_doc,
     clippy::must_use_candidate,
     clippy::needless_doctest_main,
+    clippy::needless_lifetimes,
     clippy::new_without_default,
     clippy::return_self_not_must_use,
     clippy::shadow_unrelated,