Use parent pom 28

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1755673 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 6545bb5..3a1c828 100644
--- a/pom.xml
+++ b/pom.xml
@@ -23,7 +23,7 @@
     <parent>
         <groupId>org.apache.sling</groupId>
         <artifactId>sling</artifactId>
-        <version>27</version>
+        <version>28</version>
         <relativePath />
     </parent>
 
@@ -101,7 +101,6 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
-                <version>3.0.1</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>