Updated changelog

Author: AndreMiras

CHANGELOG.md

@@ -1,4 +1,16 @@
 # Change Log
 
+## [Unreleased]
+    - Implemented new interfaces:
+        - PROPVARIANT
+        - IPropertyStore
+        - SimpleAudioVolume
+        - IAudioClient
+    - Added GetAllDevices() helper method
+    - Added code examples:
+        - audio_endpoint_volume_example
+        - simple_audio_volume_example
+        - volume_by_process_example
+
 ## [20160424]
-- Initial release
+    - Initial release