clippy 0.0.208

A bunch of helpful lints to avoid common pitfalls in Rust
error: re-implementing `PartialEq::ne` is unnecessary
  --> $DIR/partialeq_ne_impl.rs:10:5
   |
10 |     fn ne(&self, _: &Foo) -> bool { false }
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D partialeq-ne-impl` implied by `-D warnings`

error: aborting due to previous error