for adding gpg signature. update pom.xml

svn path=/trunk/; revision=1514

Author: ruolli

impl/pom.xml

@@ -231,6 +231,20 @@
                     <arguments>${release.arguments}</arguments>
                 </configuration> 
             </plugin>                    
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-gpg-plugin</artifactId>
+        <version>1.6</version>
+        <executions>
+          <execution>
+            <id>sign-artifacts</id>
+            <phase>verify</phase>
+            <goals>
+              <goal>sign</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
         </plugins>
         <resources>
             <resource>