Revert "Revert "Added column headers for host and deployment in json reports""

This reverts commit dc5dc5a6a3448111dd7d850c479ba973ccbd0777.
Revert "Revert "Adding host and deployment info to missing exists entries in the nova usage audit""

This reverts commit 8eaa1b2661cabaeceb6934118a1376c869d8cf0d.
Revert "Revert "Fixed bug with fetching deployment information in""

This reverts commit 7a4204a7260fcca111d29ba61960e1374d61e36c.
Cell and compute info added for verification failures as well.
If that is not present(request_id is not populated for an
InstanceUsage entry), the cells display '-'
Merge pull request #332 from manalilatkar/handle_none_request_id_in_audit_report

send cell and compute info for both missing exists and exists verification failure entries in the usage audit report