Update CHANGES.md

Author: simrnsethi

CHANGES.md

@@ -1 +1,10 @@
-V1.0, 2018/02/10 -- Initial release
+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.