Bump version to 0.4.0

Author: TheZoq2

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
-## [Unreleased]
+## [v0.4.0] - 2019-08-09
 
 ### Added
 
@@ -99,7 +99,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - First tagged version
 
-[Unreleased]: https://github.com/stm32-rs/stm32f1xx-hal/compare/v0.3.0...HEAD
+[Unreleased]: https://github.com/stm32-rs/stm32f1xx-hal/compare/v0.4.0...HEAD
+[v0.4.0]: https://github.com/stm32-rs/stm32f1xx-hal/compare/v0.3.0...v0.4.0
 [v0.3.0]: https://github.com/stm32-rs/stm32f1xx-hal/compare/v0.2.1...v0.3.0
 [v0.2.1]: https://github.com/stm32-rs/stm32f1xx-hal/compare/v0.2.0...v0.2.1
 [v0.2.0]: https://github.com/stm32-rs/stm32f1xx-hal/compare/v0.1.1...v0.2.0

Cargo.toml

@@ -9,7 +9,7 @@ repository = "https://github.com/stm32-rs/stm32f1xx-hal"
 documentation = "https://docs.rs/stm32f1xx-hal"
 readme = "README.md"
 edition = "2018"
-version = "0.3.0"
+version = "0.4.0"
 
 [package.metadata.docs.rs]
 features = ["stm32f103", "rt"]