Update pom.xml

pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>it.inaf.ia2</groupId>
-    <artifactId>vospace-parent-classes</artifactId>
     <parent>
         <groupId>it.inaf.ia2</groupId>
         <artifactId>vospace-parent</artifactId>
         <version>${revision}</version>
         <relativePath />
     </parent>
-
-    <version>${revision}</version>
+    
+    <groupId>it.inaf.ia2</groupId>
+    <artifactId>vospace-parent-classes</artifactId>
     <packaging>jar</packaging>
     
     <properties>