Update to parent pom 29

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1765928 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index e6f43c1..241e9a6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -23,7 +23,7 @@
     <parent>
         <groupId>org.apache.sling</groupId>
         <artifactId>sling</artifactId>
-        <version>26</version>
+        <version>29</version>
         <relativePath />
     </parent>