updated parent pom version

git-svn-id: https://svn.apache.org/repos/asf/maven/site/trunk@1754181 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index b2216c0..f40c9c4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent</artifactId>
-    <version>30-SNAPSHOT</version>
+    <version>31-SNAPSHOT</version>
   </parent>
 
   <artifactId>maven-site</artifactId>