YARN-1964. Adding changelog back in.

hadoop-yarn-project/CHANGES.txt

@@ -6,6 +6,8 @@ Release 2.6.0 - 2014-11-15
 
   NEW FEATURES
 
+    YARN-1964. Create Docker analog of the LinuxContainerExecutor in YARN. (Abin 
+    Shahab via raviprak)
 
     YARN-2131. Add a way to format the RMStateStore. (Robert Kanter via kasha)