use version 14 of plugin parent, to get source-release assembly.

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@814900 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index c40f522..77d958b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -25,7 +25,7 @@
   <parent>
     <groupId>org.apache.maven.plugins</groupId>
     <artifactId>maven-plugins</artifactId>
-    <version>13</version>
+    <version>14</version>
   </parent>
 
   <artifactId>maven-remote-resources-plugin</artifactId>