Add a test case for host argument having priority over region one.
Add a test case for host argument having priority over region one.

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