Neue Annotation @WithCredentials zum erzeugen von Credentials im Credential-plugin erstellt.
SubversionPluginTest.class is testing the latest plugin version now. I still have to port the test cases.

Added SubversionPluginTest_Version154.class to keep the old test cases for the core version 1.54.

Example for @WithCredentials in SubversionPluginTest.class

@WithCredentials is throwing exceptions now instead of logging warnings.
Merge branch 'withCredentials' of https://github.com/itgkarl/acceptance-test-harness