Set all documentation examples to 2018 edition
diff --git a/src/token.rs b/src/token.rs
index 8dc6e24..f54d02c 100644
--- a/src/token.rs
+++ b/src/token.rs
@@ -12,7 +12,7 @@
//!
//! [`ItemStatic`]: ../struct.ItemStatic.html
//!
-//! ```
+//! ```edition2018
//! # use syn::{Attribute, Expr, Ident, Token, Type, Visibility};
//! #
//! pub struct ItemStatic {
@@ -40,7 +40,7 @@
//! [`bracketed!`]: ../macro.bracketed.html
//! [`braced!`]: ../macro.braced.html
//!
-//! ```
+//! ```edition2018
//! use syn::{Attribute, Result};
//! use syn::parse::{Parse, ParseStream};
//! #