#22874 Updated version in pom files to 6.0.0-SNAPSHOT

* Updated properties for glassfish-version.properties to 6 and 0.
* Updated copyright to 2020 in files touched.
* Updated Jenkinsfile and readme

Signed-off-by: arjantijms arjan.tijms@gmail.com
diff --git a/appserver/web/gui-plugin-common/pom.xml b/appserver/web/gui-plugin-common/pom.xml
index d97983b..f24d07e 100755
--- a/appserver/web/gui-plugin-common/pom.xml
+++ b/appserver/web/gui-plugin-common/pom.xml
@@ -1,6 +1,6 @@
 <!--
 
-    Copyright (c) 1997, 2019 Oracle and/or its affiliates. All rights reserved.
+    Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
 
     This program and the accompanying materials are made available under the
     terms of the Eclipse Public License v. 2.0, which is available at
@@ -20,7 +20,7 @@
     <parent>
         <groupId>org.glassfish.main.web</groupId>
     	<artifactId>web</artifactId>
-        <version>5.1.0-SNAPSHOT</version>
+        <version>6.0.0-SNAPSHOT</version>
         <relativePath>../pom.xml</relativePath>
     </parent>
     <modelVersion>4.0.0</modelVersion>