[maven-release-plugin] copy for tag 3.0.0-alpha

upgrade to 2.1.5

release 2.1.4

Merge pull request apache#340 from Zhangxinguo/master

Add back missing mereged codes.

Upgrade version to 2.1.2

Upgrade version to 2.1.1.

upgrade to 2.1.0

checkstyle

Merge branch 'master' of https://github.com/dangdangdotcom/elastic-job

upgrade to 2.0.3