Merge pull request #4 from BarryYan/patch-1

Fix spin_loop error

src/lib.rs

@@ -4,6 +4,7 @@
 #![deny(unused_must_use, missing_docs)]
 #![allow(clippy::identity_op)]
 #![allow(dead_code)]
+#![feature(renamed_spin_loop)].   // cause core::hint::spin_loop need this feature eenabled.
 
 // #[macro_use]
 extern crate log;