Update changelog.txt

Author: simonc56

changelog.txt

@@ -1,3 +1,6 @@
+[B]0.3.7[/B] (2018-04-19)
+- Minor improvements and optimizations
+
 [B]0.3.5[/B] (2017-07-14)
 - Reworked script, changed/removed deprecated stuff
 - New property names (see description for details)
@@ -21,4 +24,4 @@
 - Correction of crash when duration value isn't properly written in database
 
 [B]0.1[/B]
-- Initial release
+- Initial release