Create new API calls to manage Nova interfaces

Create a REST interface that enables bulk creation and retrieval of instance interface information. The API should look like:

PUT /ipam/instances/{instance_id}/interfaces

At a minimum the request body should have a list of network ids and the instance's tenant_id.
The response will be a list of interfaces with interface uuid, mac address, ip address, routes etc for each interface.(Similar to the current interface api response)

To retrive the list of interfaces, the REST call will look like:

GET /ipam/instances/{instance_id}/interfaces

The response will be a list of interfaces, the same as the create call.