Update CHANGES.md

Author: simrnsethi

CHANGES.md

@@ -3,8 +3,18 @@ V1.0, 2018/02/10 -- Initial release
 V2.0, 2018/03/04 -- Second release
 
 In this release:
+
 - Added tests for AIC, BIC and Mallows Function using pytest.
 - Updated directory structure.
 - Updated function defintions since the first release.
   - Now, the user must provide the predicted values and the observed values of a model.
 - Added function descriptions.
+
+V3.0, 2018/03/11 -- Third release
+
+In this release:
+
+* Added function definitions.
+* Added few more unit tests for aic, bic and mallows.
+* Added vignette.
+* Added more documentation.