Move oslotest to test only requirements

oslotest is only used for unit testing, so
it shouldn't be in requirements.txt

Change-Id: I5073fbd93712072cec8598663590e35fc2edd08d
VM diagnostics: add methods to class to update diagnotics

Add the following methods:
    - add_cpu
    - add_nic
    - add_disk

The methods will enable the virt driver to update the object.

Change-Id: Id4ca1f188dc955590cd32c634d9c33572f93a5ef
libvirt: speed up list_instances method

Switch the list_instances method to use the new
list_instance_domains method. This removes the last
user of list_instance_ids, so delete that method.

Blueprint: libvirt-domain-listing-speedup
Change-Id: I101c42799589f01a830d974e48a1fd4b9fc60371
Merge "Move oslotest to test only requirements"
Merge "libvirt: speed up list_instances method"
Merge "VM diagnostics: add methods to class to update diagnotics"