Merge pull request #59 from KerryRJ/Fix-feature(const_fn)-has-been-removed

Fix #![feature(const_fn)] has been removed

Author: MabezDev

src/lib.rs

@@ -15,7 +15,6 @@
 //!         instructions to support IRAM usage and as optimization
 
 #![no_std]
-#![feature(const_fn)]
 #![cfg_attr(feature = "alloc", feature(allocator_api))]
 #![cfg_attr(feature = "alloc", feature(alloc_layout_extra))]
 #![cfg_attr(feature = "alloc", feature(nonnull_slice_from_raw_parts))]