Updated changelog

Author: Michael Salinger

CHANGELOG.md

@@ -1,5 +1,11 @@
 ## Changelog
 
+### 3.0.0
+* Complete re-write, with Promises and callback support
+* Dropped support for node v0.8, v0.10, v0.12
+* Supports Node v4, v6, v7, and v8.  Will continue support for node current and active LTS versions
+* For migration guide, see https://oauth2-server.readthedocs.io/en/latest/misc/migrating-v2-to-v3.html
+
 ### 2.4.1
 
 - Fix header setting syntax