Updated openstack/openstack
Project: openstack/nova  9e2a015ce3e4c7ad81ea0987e593445955814d4a

Raise Not Implemented error from V2 diagnostics API

In case any driver does not implement functionality of providing VM
diagnostics, HTTPNotImplemented error will be raised from driver.
Nova V2 API should catch the same and pass it with proper error message
for better debugging.

This patch catch & raise  HTTPNotImplemented exception for
V2 "os-server-diagnostics" API.

Adding UT also for the same.

Change-Id: I485d3487d01eba07e3c34f6ef9b5c707af54ebb7