Update changelog for v0.4.0

Author: Jonas Schievink

CHANGELOG.md

@@ -7,8 +7,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+## [v0.4.0] - 2020-06-05
+
+- Bumped the `cortex-m` dependency to v0.6.2.
 - Bumped the dependency of the `linked_list_allocator` crate to v0.8.1.
-- Removed `#![feature(alloc)]` to supress compiler warning about stability for alloc 
+- Removed `#![feature(alloc)]` to supress compiler warning about stability for alloc.
 
 ## [v0.3.5] - 2018-06-19
 
@@ -70,7 +73,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Initial version of the allocator
 
-[Unreleased]: https://github.com/japaric/alloc-cortex-m/compare/v0.3.5...HEAD
+[Unreleased]: https://github.com/japaric/alloc-cortex-m/compare/v0.4.0...HEAD
+[v0.4.0]: https://github.com/japaric/alloc-cortex-m/compare/v0.3.5...v0.4.0
 [v0.3.5]: https://github.com/japaric/alloc-cortex-m/compare/v0.3.4...v0.3.5
 [v0.3.4]: https://github.com/japaric/alloc-cortex-m/compare/v0.3.3...v0.3.4
 [v0.3.3]: https://github.com/japaric/alloc-cortex-m/compare/v0.3.2...v0.3.3