ISSUE #219: Exclude files under target directory from apache-rat check

Descriptions of the changes in this PR:

The problem is distributedlog-client and distributedlog-service have been renamed to distributedlog-proxy-client and distributedlog-proxy-server. so those files don't belong to any active modules, so they are not excluded automatically. exclude them manually.

Author: Jia Zhai <zhaijia@apache.org>

Reviewers: Sijie Guo <sijie@apache.org>

This closes #220 from zhaijack/exclude_files_under_targets, closes #219
diff --git a/pom.xml b/pom.xml
index 0a79de6..bd93cfc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -242,6 +242,7 @@
             <exclude>**/dependency-reduced-pom.xml</exclude>
             <exclude>**/org/apache/distributedlog/thrift/*</exclude>
             <exclude>**/logs/*.log</exclude>
+            <exclude>**/target/*</exclude>
             <!-- Git -->
             <exclude>.git/**/*</exclude>
             <exclude>.github/**/*</exclude>