Update CHANGELOG.md

CHANGELOG.md

@@ -1,5 +1,13 @@
 ## Emotiv SDK Community Edition Changelog
 
+#### Version 3.3.3
+* Bug fixes:
+  * Fixed bug in `IS_GetHeadsetOn` and `IS_GetBatteryChargeLevel` which always return 0
+  * Fixed bug that prevents connecting headset with firmware version `0x5xx`
+* New features and improvement:
+  * New API: `IEE_HeadsetGetSerialNumber`
+  * Speed optimization with EmotivCloudClient API and it now returns error code for easier debugging
+
 #### Version 3.3.2
 * Bug fixes:
   * Fixed unexpected failure in Mental Commands training