Switch to parent pom 26

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1722720 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 251d277..6fe29b9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -22,7 +22,7 @@
     <parent>
         <groupId>org.apache.sling</groupId>
         <artifactId>sling</artifactId>
-        <version>25</version>
+        <version>26</version>
         <relativePath/>
     </parent>