Ignore unreadable_literal lint in test code

test_suite/tests/test_de.rs

@@ -1,4 +1,4 @@
-#![allow(clippy::decimal_literal_representation)]
+#![allow(clippy::decimal_literal_representation, clippy::unreadable_literal)]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};

test_suite/tests/test_ser.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::unreadable_literal)]
 #![cfg_attr(feature = "unstable", feature(never_type))]
 
 use std::cell::RefCell;