Update maven-checkstyle-plugin to 2.12.1 from 2.9.1 which fixes [MCHECKSTYLE-172]: Checkstyle Plugin 2.8+ generates an additional aggregate report.
Update maven-checkstyle-plugin to 2.12.1 from 2.9.1 which fixes [MCHECKSTYLE-172]: Checkstyle Plugin 2.8+ generates an additional aggregate report.

git-svn-id: a66ef3f0e6c00b14098e182847b4bd646263fa09@1622042 13f79535-47bb-0310-9956-ffa450edef68

apache/commons-pool,apache/commons-pool,apache/commons-pool