Fix clippy needless_lifetimes lint (shssoichiro#89)

Author: FreezyLemon

src/codec/traits.rs

@@ -7,7 +7,7 @@ pub trait Decoder<T> {
     fn decoder(self) -> Option<Codec<T>>;
 }
 
-impl<'a> Decoder<UnknownType> for &'a str {
+impl Decoder<UnknownType> for &str {
     fn decoder(self) -> Option<Codec<UnknownType>> {
         decoder::find_by_name(self)
     }
@@ -39,7 +39,7 @@ pub trait Encoder<T> {
     fn encoder(self) -> Option<Codec<T>>;
 }
 
-impl<'a> Encoder<UnknownType> for &'a str {
+impl Encoder<UnknownType> for &str {
     fn encoder(self) -> Option<Codec<UnknownType>> {
         encoder::find_by_name(self)
     }

src/lib.rs

@@ -4,6 +4,8 @@
 #![allow(clippy::too_many_arguments)]
 // FFI Types may differ across platforms, making casts necessary
 #![allow(clippy::unnecessary_cast)]
+// This lint sometimes suggests worse code. See rust-lang/rust-clippy#13514
+#![allow(clippy::needless_lifetimes)]
 
 #[macro_use]
 extern crate bitflags;