Fix the ClientConfigProviderTestJarHelper to work on Windows

The ClientConfigProviderTestJarHelper used in some authentication launches a new process and creates a large class path which doesn't work well on Windows. This should be analyzed and possibly rewritten. The JAR's created invoke an entry point which simply outputs text to stdout. There might be a better way to handle this. One option might be to return the HTTP status code as the exit code for the process. However, relying on the output doesn't feel quite right.

Another thing to look at is it uses JUnit Assertions which are not enabled for the JVM.