CHANGELOG.md in routemaster-drain-3.6.3 vs CHANGELOG.md in routemaster-drain-3.6.4

@@ -1,8 +1,15 @@
 ### HEAD
 
 _A description of your awesome changes here!_
 
+### 3.6.4 (2018-10-23)
+
+Features:
+
+- Allow specification of User-Agent through environment variable
+- Add fallback values for User-Agent header in API client
+
 ### 3.6.3 (2018-10-17)
 
 Bug fix:
 
 - Allow all middleware classes to be initialised in the same format