Add host field to ComputeNode

In order to remove the Service dependency, we need to add
the host field to ComputeNode when creating an entry

Partially-Implements blueprint detach-service-from-computenode

Change-Id: I353eb87f915a5ab7d492c2dbd028a839aa5041a6
fix pep8 errors that apparently slipped in

Apparently, a couple of H302 issues have slipped into Nova, possibly
due to hacking releases or a bad merge commit. Fix these as they are
blocking some other patches.

Change-Id: Icc42e060492bc74febc9414b63970ee71fb9c27c
Merge "fix pep8 errors that apparently slipped in"
objects: introduce numa pages topology as an object

Introduces object NUMAPagesTopology also remove the one
from hardware.py which will be not used.

Work-Item: Enhance libvirt driver to report available
           large pages per NUMA node in the host state data

Change-Id: I004c87c5c5b2b42fda04b5754b77a83fadd44281
Partial-Implement: blueprint virt-driver-large-pages
Merge "Add host field to ComputeNode"
Merge "objects: introduce numa pages topology as an object"