updated changelog

Author: mediumTaj

CHANGELOG.md

@@ -0,0 +1,23 @@
+Change Log
+==========
+## Version 0.2.0
+_2017-04-25_
+
+* New: Abstracted `Visual Recognition` service.
+* New: Completed `Speech to Text` abstraction.
+* New: Completed `Conversation` abstraction.
+* New: Integration and Unit tests.
+* New: Example service calls.
+* Fix: Enabled fail build on failed test in AppVeyor.
+* Fix: Fixed all integration and unit tests.
+
+## Version 0.1.0-alpha
+_2017-02-12_
+
+Initial alpha release of .NET Standard SDK. Service supported include:
+* Conversation
+* Speech to Text
+* Text to Speech
+* Language Translator
+* Personality Insights
+* Tone Analyzer