FLUME-2368. Update CHANGELOG for 1.5 release
FLUME-2368. Update CHANGELOG for 1.5 release

szaboferee/flume,szaboferee/flume,iaiengxia/flume,tinawenqiao/flume,tinawenqiao/flume,tmgstevens/flume,iaiengxia/flume,iaiengxia/flume,szaboferee/flume,iaiengxia/flume,tmgstevens/flume,tinawenqiao/flume,tmgstevens/flume,tinawenqiao/flume,tmgstevens/flume,szaboferee/flume