Add changelog entry for v0.1.4 release

Author: eldruin

CHANGELOG.md

@@ -7,6 +7,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ...
 
+## [v0.1.4] - 2019-06-12
+
+### Fixed
+- Restored compatibility with Rust 1.31.0
+
 ## [v0.1.3] - 2019-05-14
 
 ### Added
@@ -85,7 +90,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 - Initial release
 
-[Unreleased]: https://github.com/japaric/libm/compare/0.1.3...HEAD
+[Unreleased]: https://github.com/japaric/libm/compare/v0.1.4...HEAD
+[v0.1.4]: https://github.com/japaric/libm/compare/0.1.3...v0.1.4
 [v0.1.3]: https://github.com/japaric/libm/compare/v0.1.2...0.1.3
 [v0.1.2]: https://github.com/japaric/libm/compare/v0.1.1...v0.1.2
 [v0.1.1]: https://github.com/japaric/libm/compare/v0.1.0...v0.1.1