qemu.tests: Add a test case for collecting Windows guest information

This case is used to collect guest information in test loop. This will
help the test runner have more information about guest os version and
dirver version informations(virtio drivers version etc.).

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Merge pull request #137 from ypu/windows_info

qemu.tests: Add a test case for collecting Windows guest information