Prepare for next release

CHANGELOG.md

@@ -3,9 +3,15 @@ CHANGELOG
 
 This changelog references the relevant changes done in PHP-ML library.
 
-* 0.2.2 (in plan/progress)
+* 0.3.1 (in plan/progress)
     * feature [Regression] - SSE, SSTo, SSR  - sum of the squared
 
+* 0.3.0 (2017-02-04)
+    * feature [Persistency] - ModelManager - save and restore trained models by David Monllaó
+    * feature [Classification] - DecisionTree implementation by Mustafa Karabulut
+    * feature [Clustering] - Fuzzy C Means implementation by Mustafa Karabulut
+    * other small fixes and code styles refactors
+
 * 0.2.1 (2016-11-20)
     * feature [Association] - Apriori algorithm implementation
     * bug [Metric] - division by zero