OpenStack - Ensure inventory is collected for all tenants.

@Fryguy @blomquisg please review.

For OpenStack refresh, ensure inventory is collected for all of the
tenants the EMS can access.

Extended OpenstackHandle to include tenant iterators.
Updated EmsOpenstack and the openstack parser to use the OpenstackHandle accordingly.
Updated spec tests and rerecorded vcr cassettes.
My apologies... It's not inconsistent data in the spec, it's when anything goes wrong in the refresher / parser.  If you put a ```raise "Some Error"``` anywhere in the parser, that error will be rescued and the spec will fail with:
```ruby
VCR::Errors::UnusedHTTPInteractionError:
       There are unused HTTP interactions left in the cassette:
```