Make rustc lints happy on latest nightly

Author: tyranron

tests/integration/tests/arc_fields.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code, reason = "GraphQL schema testing")]
+
 use std::sync::Arc;
 
 use juniper::{GraphQLInputObject, graphql_object};

tests/integration/tests/infallible_as_field_error.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code, reason = "GraphQL schema testing")]
+
 use std::convert::Infallible;
 
 use juniper::graphql_object;