Fix changelog release history

CHANGELOG.md

@@ -5,14 +5,18 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
-## [0.4.1] - 2019-01-21
+## [0.5.1] - 2019-01-21
 ### Fixed
 - Fixed front end to allow ppn control to remain blank
 
-## [0.4.0] - 2019-01-09
+## [0.5.0] - 2019-01-09
 ### Added
 - Added control to select number of CPUs
 
+## [0.4.0] - 2018-09-13
+### Added
+- Added Abaqus 2018 to the app.
+
 ## [0.3.0] - 2018-03-09
 ### Added
 - Added Abaqus 2017 to the app.
@@ -71,8 +75,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 - Initial release!
 
-[Unreleased]: https://github.com/OSC/bc_osc_abaqus/compare/v0.4.1...HEAD
-[0.4.1]: https://github.com/OSC/bc_osc_abaqus/compare/v0.4.0...v0.4.1
+[Unreleased]: https://github.com/OSC/bc_osc_abaqus/compare/v0.5.1...HEAD
+[0.5.1]: https://github.com/OSC/bc_osc_abaqus/compare/v0.5.0...v0.5.1
+[0.5.0]: https://github.com/OSC/bc_osc_abaqus/compare/v0.4.0...v0.5.0
 [0.4.0]: https://github.com/OSC/bc_osc_abaqus/compare/v0.3.0...v0.4.0
 [0.3.0]: https://github.com/OSC/bc_osc_abaqus/compare/v0.2.0...v0.3.0
 [0.2.0]: https://github.com/OSC/bc_osc_abaqus/compare/v0.1.0...v0.2.0