Test harness should set the Configuration directory to use the test temp dir by default

Currently the UserConfiguration references the current users home directory while running tests - it should use the available system property while running tests in order to direct the config dir to a temp location for that test execution:

   static final String USER_CONFIG_PATH = "org.jboss.forge.addon.configuration.USER_CONFIG_PATH";


         String property = System.getProperty(USER_CONFIG_PATH);