qemu-iotests: Test creating floppy drives

This tests the different supported methods to create floppy drives and
how they interact.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1477386868-21826-5-git-send-email-kwolf@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>