add flattened pom plugin

Signed-off-by: Raymond Auge <rotty3000@apache.org>
diff --git a/.gitignore b/.gitignore
index 7081da0..f01ca9b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 *.iml
 .classpath
 .project
+.flattened-pom.xml
 .settings/
 */bin/
 **/build/
diff --git a/pom.xml b/pom.xml
index 893dd4b..8b08d9b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -487,6 +487,32 @@
                 </plugin>
             </plugins>
         </pluginManagement>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>flatten-maven-plugin</artifactId>
+                <version>1.2.5</version>
+                <configuration>
+                    <flattenMode>oss</flattenMode>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>flatten</id>
+                        <phase>process-resources</phase>
+                        <goals>
+                            <goal>flatten</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>flatten-clean</id>
+                        <phase>clean</phase>
+                        <goals>
+                            <goal>clean</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
     </build>
 
     <profiles>