Update CHANGELOG notes

Author: mmistakes

CHANGELOG.md

@@ -1,3 +1,13 @@
+## [3.1.0](https://github.com/mmistakes/minimal-mistakes/releases/tag/3.1.0)
+
+### Enhancements
+
+- Updated [Font Awesome](https://fortawesome.github.io/Font-Awesome/whats-new/) to version 4.6.1
+- Added optional GitHub and Bitbucket links to footer if set on `site.author` in `_config.yml`.
+
+### Bug Fixes
+- Fixed Bitbucket URL typo in author sidebar.
+
 ## [3.0.3](https://github.com/mmistakes/minimal-mistakes/releases/tag/3.0.3)
 
 ### Enhancements