Catch ssh exception and detach in min scenario

The test_minimum_basic test goes through a number of tests however
doesn't do any clean up if a failur occurs.  The master clean-up
routine is ok, but it doesn't account for things like attached volumes.

One issue here is that the ssh_to_server times out do to some other
problem and raises an SSHTimeout exception.  This exception isn't dealt
with, the test dumps out and tries to cleanup by deleting the instance
and the volume, but the volume-delete will fail because it's status is
still in-use.

This exposes another problem, it seems that nova delete will clean up
an instance but fairly regular neglect to detach the volume. This patch
add an addCleanup() call to nova.volume_detach.

Change-Id: I76d19f096d6cb4122eea2e7e5de4eb37b97a4b87
Partial-Bug: #1213215
remove Nova v3 XML testing

this removes the XML base clients, as well as skips any Nova v3
XML tests so that we can actually propose the patch to remove
v3 XML from Nova.

Part of bp:remove-v3-xml-api

Change-Id: I68ff62846346bac94a3b91366aa03f022f3f32b7
remove the nova v3 xml tests from the code

this is phase 2 in removing the xml tests from the code, should
give us an idea on the run time differences now that testr will
pull these out of the scheduler.

Part of bp:remove-v3-xml-api

Change-Id: I0fbb19b6d0b6dbbcb9c9c9e0cb86690abc4790a0
Merge "Catch ssh exception and detach in min scenario"
Merge "remove the nova v3 xml tests from the code"