Adding 2.8 section in CHANGES.txt

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -426,6 +426,18 @@ Trunk (Unreleased)
 
     HADOOP-8589. ViewFs tests fail when tests and home dirs are nested (sanjay Radia)
 
+Release 2.8.0 - UNRELEASED
+
+  INCOMPATIBLE CHANGES
+
+  NEW FEATURES
+
+  IMPROVEMENTS
+
+  OPTIMIZATIONS
+
+  BUG FIXES
+
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -313,6 +313,18 @@ Trunk (Unreleased)
     HDFS-4681. TestBlocksWithNotEnoughRacks#testCorruptBlockRereplicatedAcrossRacks 
     fails using IBM java (Ayappan via aw)
 
+Release 2.8.0 - UNRELEASED
+
+  INCOMPATIBLE CHANGES
+
+  NEW FEATURES
+
+  IMPROVEMENTS
+
+  OPTIMIZATIONS
+
+  BUG FIXES
+
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/CHANGES.txt

@@ -245,6 +245,18 @@ Trunk (Unreleased)
 
     MAPREDUCE-6078. native-task: fix gtest build on macosx (Binglin Chang)
 
+Release 2.8.0 - UNRELEASED
+
+  INCOMPATIBLE CHANGES
+
+  NEW FEATURES
+
+  IMPROVEMENTS
+
+  OPTIMIZATIONS
+
+  BUG FIXES
+
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/CHANGES.txt

@@ -45,6 +45,18 @@ Trunk - Unreleased
     YARN-2428. LCE default banned user list should have yarn (Varun
     Saxena via aw)
 
+Release 2.8.0 - UNRELEASED
+
+  INCOMPATIBLE CHANGES
+
+  NEW FEATURES
+
+  IMPROVEMENTS
+
+  OPTIMIZATIONS
+
+  BUG FIXES
+
 Release 2.7.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES