Added inventory collection for OpenStack cloud storage.

Added collection of: volumes, volume snapshots, object store containers and object store objects.
Rubocop cleanup.
Check for nil arg passed to link_volumes_to_base_snapshots method.
Fixed issues uncovered by spec tests.
Fixed CloudVolume spec.

Accounting for the fact that cloud volumes are now connected to
VMs through disks, as opposed to directly.
Rebased cloud_storage to master

Updated cloud storage code to use tenant updates of OpenstackHandle.
Rubocop clean up.
SCVMM scheduled EMS refresh.

A mechanism was needed to refresh the SCVMM provider given that event support will not be in the 3.1 release. I have configured a 4 minute schedule but am open to negotiation on the frequency. On one hand we need to bear in mind that an EMS refresh can take more than 4 minutes but on the other hand we can't wait too long after a VM power operation.