To facilitate opaqueness of resource provider generation internals, we
need to return the (initial) generation when a provider is created. For
consistency with other APIs, we will do this by returning the entire
resource provider record (which includes the generation) from POST
/resource_providers.
Change-Id: I8624e194fe0173531c5aa2119c903e3c68b8c6cd
blueprint: generation-from-create-provider
388db7e6e2