Add new release skeleton to Changelog

Author: effigies

Changelog

@@ -24,6 +24,25 @@ Gerhard (SG) and Eric Larson (EL).
 
 References like "pr/298" refer to github pull request numbers.
 
+Upcoming Release
+================
+
+New features
+------------
+
+Enhancements
+------------
+
+Bug fixes
+---------
+
+Maintenance
+-----------
+
+API changes and deprecations
+----------------------------
+
+
 2.1 (Monday 22 August 2016)
 ===========================