remove unnecessary lines

examples/dom/src/lib.rs

@@ -1,6 +1,4 @@
 
-use web_sys;
-
 use wasm_bindgen::prelude::*;
 
 // Called by our JS entry point to run the example

examples/fetch/src/lib.rs

@@ -1,8 +1,3 @@
-
-
-
-
-use web_sys;
 #[macro_use]
 extern crate serde_derive;
 

examples/guide-supported-types-examples/src/lib.rs

@@ -1,7 +1,5 @@
 #![allow(unused_variables, dead_code)]
 
-use wasm_bindgen;
-
 pub mod bool;
 pub mod boxed_js_value_slice;
 pub mod boxed_number_slices;