change the test-config to allow to restrict tests to a specific environment

we just need groups/categories to mark that a test should be executed only with specific environments. even though a java-ee6 application server has to be able to run all tests in theory, we have to exclude some tests because there are e.g. packaging issues, issues with arquillian, remote execution issues,... . if a test isn't restricted to an environment, no category is used for the test-class.