Update codegen to 2018 edition
diff --git a/codegen/src/parse.rs b/codegen/src/parse.rs
index eff8539..08aefd1 100644
--- a/codegen/src/parse.rs
+++ b/codegen/src/parse.rs
@@ -1,7 +1,8 @@
use crate::types;
use indexmap::IndexMap;
-use syn::{Data, DataStruct, DeriveInput, Ident, Item};
+use quote::quote;
+use syn::{parse_quote, Data, DataStruct, DeriveInput, Ident, Item};
use std::collections::BTreeMap;
use std::fs::File;
@@ -246,6 +247,7 @@
use crate::types;
use proc_macro2::TokenStream;
+ use quote::quote;
use syn;
use syn::parse::{Parse, ParseStream, Result};
use syn::*;