Add test_list_containers test case for LXD
Add test_list_containers test case for LXD

apache/libcloud,mistio/libcloud,andrewsomething/libcloud,mistio/libcloud,andrewsomething/libcloud,andrewsomething/libcloud,Kami/libcloud,apache/libcloud,Kami/libcloud,apache/libcloud,Kami/libcloud,mistio/libcloud