Add cobertura-maven-plugin and upgrade findbugs-maven-plugin from 1.2 to 2.3.1

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/chain/trunk@1005280 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 6c82c47..968016a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -283,8 +283,17 @@
             </plugin>
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
+                <artifactId>cobertura-maven-plugin</artifactId>
+                <version>2.4</version>
+                <configuration>
+                    <threshold>Normal</threshold>
+                    <effort>Default</effort>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
                 <artifactId>findbugs-maven-plugin</artifactId>
-                <version>1.2</version>
+                <version>2.3.1</version>
                 <configuration>
                     <threshold>Normal</threshold>
                     <effort>Default</effort>