Make clippy happy

src/binread.rs

@@ -2,12 +2,13 @@ use Result;
 use block::Block;
 use ops::{Operation,num_to_op};
 
-#[allow(unknown_lints,len_without_is_empty)]
 pub trait BinReadable {
     fn get(&mut self) -> Result<u8>;
     fn cur(&self) -> usize;
     fn len(&self) -> usize;
     fn slice(&mut self, len: usize) -> &[u8];
+
+    fn is_empty(&self) -> bool;
 }
 
 pub trait BinRead {