Some small test improvements

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1535701 13f79535-47bb-0310-9956-ffa450edef68
Adding serial version id

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1535702 13f79535-47bb-0310-9956-ffa450edef68
KARAF-2393 Upgrade to maven bundle plugin 2.4.0

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1535714 13f79535-47bb-0310-9956-ffa450edef68