add test checking file disk is created

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-components/trunk@1447470 13f79535-47bb-0310-9956-ffa450edef68
add files and ensure file contains data

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-components/trunk@1447474 13f79535-47bb-0310-9956-ffa450edef68