Changelog updates since v5.0.1 (#45)

Author: milesfrain

CHANGELOG.md

@@ -5,12 +5,15 @@ Notable changes to this project are documented in this file. The format is based
 ## [Unreleased]
 
 Breaking changes:
+  - Added support for PureScript 0.14 and dropped support for all previous versions (#41)
 
 New features:
 
 Bugfixes:
 
 Other improvements:
+  - Migrated CI to GitHub Actions and updated installation instructions to use Spago (#42)
+  - Added a CHANGELOG.md file and pull request template (#44, #45)
 
 ## [v5.0.1](https://github.com/purescript/purescript-catenable-lists/releases/tag/v5.0.1) - 2019-01-25