Fixed attribute passing for add_interface

Server model has an `add_interface` method. This method allows attributes to be passed so you can configure options on the interface. Unfortunately it doesn't pass these options to the create_interface call. This in turn leaves `attributes` empty for `create_vm.rb#create_interface` and subsequently `create_vm.rb#create_nic_backing`. When you define a `DistributedVirtualPortgroup` as the network attribute, and `create_nic_backing` doesn't have `attributes[:datacenter]`, you will end up with a newly created StandardPortgroup instead of the correct `DistributedVirtualPortgroup` in your Backing info for the interface. To solve this you will need to pass along the `datacenter: 'name-your-dc-here'` param when you call server.add_interface, along with `type`, and `network`. 

Tested in ESX 5.5
Adds openstack_region parameter to OpenStack Identity Service
Merge tag 'v1.24.0' into patch-1

Catching up with v1.24.0
[google|dns] Add Project resource

- Add Project models, requests and tests
[google|dns] Add Zone model

- Add Zone model and test
- Refactor zone mock request to use a single Hash
- create_managed_zone requires description, don't default it to blank
- Fix indentation
[google|dns] Add Record resource

- Add Record models, requests and tests
- Add #record method (and associated test) to Zone
[google|dns] Add Change resource

- Add Change models, requests and tests
- Add #changes method (and associated test) to Zone
- Add #destroy method (and associated test) to Zone
- Add #modify method (and associated test) to Zone
- Add #save method (and associated test) to Zone
[google|dns] Add examples
added support for searching of images in fogdocker
Merge pull request #3196 from witlessbird/docker-image-search

added support for searching of images in fogdocker
Added GovCloud region to acceptable AWS list
Merge pull request #3195 from frodenas/gce_dns

[google|dns] Add missing models, requests and tests
[openstack] add remove header if setting directory back to private. Without it directory once public will stay like that forever.
Merge pull request #3197 from amdonov/master

Added GovCloud region to acceptable AWS list
Docker: Support for logs/top operations

In order to test this properly, responses from the mock return values
closer to what the API actually returns. Examples are from Remote API
1.18.

downcasing hash keys cannot be performed on all Docker API operations so
now it will only be done where the top element is a hash. Logs, top, and
many others will not return a hash.
Merge pull request #3199 from sulphur/master

[openstack] add remove header if setting directory back to private
Merge pull request #3202 from eLobato/docker-logs

Docker: Support for logs/top operations
Requiring fog/version
Merge pull request #3206 from plribeiro3000/edge-build

Requiring fog/version
Using `fog-xml`