[examples] julia_set - port to rust 2018

examples/julia_set/Cargo.toml

@@ -2,6 +2,7 @@
 name = "julia_set"
 version = "0.1.0"
 authors = ["The wasm-bindgen Developers"]
+edition = "2018"
 
 [lib]
 crate-type = ["cdylib"]

examples/julia_set/src/lib.rs

@@ -1,6 +1,3 @@
-extern crate wasm_bindgen;
-extern crate web_sys;
-
 use std::ops::Add;
 use wasm_bindgen::prelude::*;
 use wasm_bindgen::Clamped;