libvirt.tests: Add volume application test module(part 1).

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
tp-libvirt: Add attach-disk action with created volume

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
tp-libvirt: Add vm install action with created volume

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
tp-libvirt: fix typo for install test of volume

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
Merge pull request #60 from liyangfnst/volume_attach

Add volume application test module (attach-disk)